# Personal Shield Generators effects on Strategy/Logistics/Tactics

In World War II shield generators were discovered. As their durability or surface area coverage scales up the cost exponentially increases. By their nature they wrap around the target approximately, providing a rough silhouette of their subject. Protection is strictly against kinetic impacts, and the protection scales up directly with both the force of the impact and against piercing impacts (impacts with the same force but far smaller surface area for the force will be blocked to a greater degree) to a proportionate degree: a punch won't be stopped meaningfully, but a pistol shot will feel like a sharp tap. Shields cannot be stacked as they interfere with one another. Projection is very close range, and so they cannot remotely support a target. Leaving a shield on damages it, but at a very slow rate. The protection provided by a shield is largely unpredictable with significant variation found between real-world uses.

Due to the exponential increase for both surface area and durability, shields would almost always be impractical for vehicle protection.

A standard implementation of a shield follows the following more specific description:

• About the size and weight of a case of large binoculars (~5 lb).
• They can protect "about two direct hits from a rifle at mid range" (a poorly-defined approximation due to the high variance in the shields' real-world durability)
• They can last about 72 hours if left running continuously, never taking damage
• They cost about 2-3 times that of a standard military rifle of that era
• Replenishing the core (thus regaining the durability) costs about the same as a military rifle of that era

A more or less durable shield can be produced at more or less cost (again, following an exponential curve), but this cost depends on economies of scale, and so the shield generators are only affordable if produced en masse.

Given such technology entering into WWII, how would strategy, tactics, and logistics of this era change to accommodate it? Would one nation or another be more or less affected by this technological discovery?

Note: This is not tagged as science-based intentionally as the concept is non-scientific. However I'm fine with science comments (such as what it might protect and might not due to forces involved) following hand waving of this technology's existence.

• You say that "impacts with the same force but far smaller surface area for the force will be blocked to a greater degree." So if I increase the velocity of the same size bullet (e.g. a 30-06 has more KE than a same sized 7.62 round), would the 30-06 or 7.62 be more effective against the shield? – kingledion Jul 28 '16 at 18:12
• @kingledion The shield's ability to stop an object (at least until its own durability gives out) trends towards 100% as the velocity increases and the surface area of the impact decreases. Thus a pistol round would feel like a sharp tap, but a punch might only be mildly hampered. Does that clarify it? If so I'll add it to the question. – Ranger Jul 28 '16 at 18:14
• How does the shield's ability to stop an object trend if the velocity increases but the surface area of impact stays the same? Example for a ~180 grain bullet (that is the weight of the bullet, about 12 grams) I can shoot it at 373m/s, 835J from a .45 pistol or 820 m/s, 3949J from a 30-06 rifle. Are you suggesting that the pistol, because it is less energetic, would do more damage to the shield? – kingledion Jul 28 '16 at 18:21
• I am reminded of the personal Shields in "Dune" ... – Joe Jul 28 '16 at 18:23
• Given the force/area properties of the shield, I should think dum dum bullets would make a bit of a comeback, after which the shield would be much less of an advantage. – Nathaniel Feb 17 '18 at 3:16

This is really a question of economics. Would such a device be practical to be produced in a large scale.

I myself am a German economic historian, and I specialize in pre-war economies. Thus I will answer from the German perspective, as that is the only country which I can, in good faith, answer for.

In short, yes.

But the reason for it is striking. Assuming that it is made with no "rare earth elements," or semi-rare metals (which based on the weight, I grant, would be a stretch), the device could have changed the war.

Correct me if this is a faulty assumption, but I assume this device could enter mass production in 1938. Thus, if it could effectively stop a standard rifle bullet, the German blitz into Norway would have met with far less casualties that it did. The Norwegian invasion cost about 3 divisions of infantry in casualties, though about a third of the injuries sustained were such than the troops reentered service within a year. If that number could have been reduced to a single division, or less, the invasion of Russia could have occurred roughly four months earlier, and would have catalyzed more momentum due to its proximity to Hitler's Lebensraum speech.

The reason I argue that this would have been effective in Norway is that by 1940, German economic production had picked up the slack left by the slump. As economist Mark Harrison points out, the German economy was outproducing all the major belligerents at that time (in non-naval war materials. If naval goods are analyzed, Britain led production). Thus, an economy of scale (to use the modern term) would be easily achieved, provided a product life-cycle of about 3 years. Germany, however, was virtually an autarky state, operating under a similar economy as cold war era Russia. Thus, the product life-cycle would be atypical, and a new product would emerge in 1941, and again in '44.

All that aside. The reason why it would have been useful against the Norwegians, is that the Norwegian army relied on 1) artillery batteries, and 2) the Norwegian bolt action rifle, similar to the k98, but with less range, and a slightly smaller round. The rifle was reliable at medium range, but with the springtime mists and fog, ineffective at long range (the reason that a scoped variant was virtually nonexistent). Because of the artillery, the blitz was slowed. Also, Panzer-1 units were increasingly hampered by ambushes, and turret gunners received the highest casualties. Such a shield for Panzer-1 gunners would have prevented this slowdown, and reduced the length of the blitz by several months, as the Panzer-1's would have been able to deal with the artillery, and Panzer-3 crews could have dealt with the military buildings and bunkers (as was the case with the subjugation of France).

For those not into military and economic history, dispel your notions of German Panzers from World of Tanks and the History Channel. The Panzer-1 was basically a lightly armored mobile machine gun, capable of 35-40 mph in its original platform and 30-30 mph in its variant-1 version, which added a small turret on top an an MG-34 machine gun. The Panzer-3 was more on par with the Sherman, but with a longer barrel, thicker treads, and a stronger motor, giving in speeds of close to 30 mph. There were seven variants, but only two at the time of the Norwegian invasion, and none that were actually deployed. Even the Panzer-3's saw limited deployment, and never achieved an economy of scale, as production was shifted to accommodate the Panzer-4's, which became iconic after the war.

That aside, in the war against Russia, the shield would have been only of limited use. Nonetheless, the extra divisions from Norway (and extra units from Greece (saved for the same reason as Norway)), could have tipped the balance of power against Russia. But as Historian Richard Overy warns, pinning hope on only one element to form any kind of meaningful shift in any preposterous "what-if" scenario, runs the risk of missing other elements that would have been neglected if more energy was put into that one element.

Hence, the weakness of this "shield argument," is that the cost of the unit is more than just a rifle. It is in addition of a rifle. It is the maintenance for when shrapnel damages the units, it is the decrease in economic resource mobilization efficiency. But despite this, I still believe the Germans would have invested in it, for the same reason they invested in Panzer-1's and 3's, it had the potential to give them an edge. To say it would have won them the war, however, is preposterous. I doubt, even, that tactics would have changed very much to account for its presence, just as Russian and American tactics didn't change with the introduction of the sturmgewehr.

So the reason why the Germans would use it? It might give them an edge. That is it. Did the sturmgewehr (the worlds first assault rifle, with good range, accuracy, rate of fire, and stopping power, all in a package light enough to be carried by, even run with, a soldier) give them an edge? No. So why develop it? Because it might have. In the words of British Historian Adam Tooze, "... the Nazi economy ultimately collapsed because the Nazis pursued this and that idea, solution, technology, initiative, but certainly not economic growth, and eventually reaped the wages of destruction."

And while I can only speak for Germany, I suspect an analysis of the other 5 major belligerents would present a similar view: if used, it would not have a significant impact -- even though it is capable a reducing bullet impact.

• Your analysis is outstanding. But I'm confused...first you say it could have made a difference "...the device could have changed the war." But then, in conclusion, you say ultimately, it would have made no difference, "I doubt, even, that tactics would have changed very much to account for its presence, just as Russian and American tactics didn't change with the introduction of the strumawahr." Personally, I think your first assertion was more on par. Whether or not it would have made enough difference to change the outcome would greatly depend on more factors than can be analyzed. – Steve Mangiameli Aug 4 '16 at 14:28

I would guess pretty much like modern soft/hard armor affect warfare today.

When firearms were introduced into the battlefield, armor (steel armor in this case) was still used. It continued to be used because early firearms were inaccurate, and inefficient. Most combat still took the form of hand-to-hand engagements with melee weapons (spears, halberds, etc.)

As firearms get better, production lines were established, mass production of accurate, affordable firearms improved, and armor was slowly phased out. Bullets penetrated steel armor. Charging armored knights couldn't survive against massed rifle/musket fire from a square of infantry.

Matter of fact, military armor was all but gone until WW1, when it was discovered that most military casualties in that war were caused by fragments from artillery shells hitting Soldiers' heads. Thus the steel helmets were introduced to stop this threat. Note that a properly aimed and fired rifle round, or even pistol round of that era (if close enough) could still penetrate those helmets. But the armor (helmet in this case) was designed to specifically counter artillery shell frags because those were the most effective casualty producing weapon at that time. Matter of fact, 56% of all casualties were caused by shell fragments, with machine guns close behind. Rifles and pistols caused relatively few casualties (a lot of factors go into this, but I won't get into it because it's a whole other discussion).

WW2 was almost the same. Armies are trained and equipped for the previous war, so they went into battle, mostly, with WW1 era personal equipment (in the beginning that is). We don't see widespread use of personal protective equipment other than helmets in any WW2 armies, aside from flak jackets issued to flight crews and sailors. The infantry pretty much only had helmets. As with the previous war, shell fragments (from artillery mostly), were the most effective casualty producing weapon of that war.

Matter of fact, we didn't see widespread use of extensive PPE until the Korean War, when the US started issuing flack jackets. Even then they were issued mostly as a defense against artillery fire, and not necessarily accurate rifle fire. (They could stop pistol rounds, but, pistols are almost useless in serious combat, thus pistol fire isn't really a worthwhile risk factor to consider).

It was only in 1996 that the US widely issued the Interim Small Arms Protective Insert (ISAPO) to be worn over the then issued PASGT armor designed to defeat small arms fire. But until the introduction of the Interceptor Body Armor, and the completion of that vest's issue throughout the Armed Forces, most infantryman did not have ballistic protection against rifle/machine gun fire.

Now that we're done with the real world history let's work on your question.

Due to the constraints you place on the Personal Protective Shield System (PPSS, pronounced the PISS by the troops), at first they will only be limited to certain units doing certain things that are of higher risk in encountering small arms fire than General Purpose Forces. In World War 2, these would be Raiders, Rangers, and other Special Operations Teams (SAS, SOE commando teams, OSS teams, etc). These units were expected to get into close combat with enemy troops in places where artillery fire was unlikely to happen (behind enemy lines, say). Some of these men will fall in battle, and ze Chermans will recover some functioning PISS units despite the precautions taken against this eventuality (troops were ordered to destroy their PISS before capture, for instance) and certain German units will also have PISS.

As the war continues, and as you say, mass production of PISS is perfected, more and more troops will have access to them. Their PISS wouldn't be as strong as the special folks' PISS, of course, but something is better than nothing, so you will see shields used in both sides of the war.

Tactics will eventually be adapted to counter this. The Germans would probably introduce semi automatic rifles much sooner, for instance, in order to facilitate rapid engagement against shielded troops. Marksmanship training would have emphasized on accurately hitting enemy troops multiple times with rifle fire in order to collapse their shields and kill them.

Assault tactics will also change a little as troops can now take more risks due to their shields taking some of the enemy fire.

Logistically, nothing much would change - except the curses thrown your way (or whoever was in charge) by logistics officers who now have several items added to their lists (PISS units, extra batteries, maintenance kits, rebuild kits, etc.). Armorers will now have an extra course to go through in their training (Shield Maintenance, Repairs, and Rebuild), or a Shield Technician MOS is added to the TO&E. With all the logistical nightmares that entails. (I kid. Mostly.)

Aside from that, nothing much would change. Massed artillery will continue to chew up troops (inducing slightly fewer casualties though, since some of those who would've been wounded by artillery fire, now escape unscathed). Tanks will continue to kill tanks. Firebombing would've killed about the same number of civilians. And the atomic bombs over Japan would've done the same, shield or no shield.

As technology advances, and we go into the modern era, I expect troops to still wear some form of armor under their shields (the Military is as risk averse as anyone who is closely under Congressional scrutiny), but like what we see today with armor, PISS will still mostly be a military issue. Insurgents will defeat the shields the same way insurgents now defeat PPE: Hitting troops where either the shields are weak, or multiple times to collapse them, or with a weapon of sufficient power to collapse the shield in one shot. IEDs will still chew up troops (I doubt that a shield will stop a hit from an EFP (explosively formed penetrator charge, or protect folks in Humvees from IEDs made from multiple 155mm artillery shells taped together). As before, the special folks will have better PISS than the general purpose folks (lighter, stronger, lasts longer!) and this technology will eventually dribble down to the line grunts.

About the only change is that newer generation logistical officers no longer curse you (or whoever is in charge) because now the PISS is in the TO&E so long, it's basically just another line item.

• I was debating between you and the accepted answer for the bounty. In the end I was going to offer multiple bounties since you both had extremely high quality answers, but Stack Overflow technically allows this but it... has really weird rules about multiple bounties that I can't get around that I discovered after I awarded the initial bounty. I wish I could award this answer as well! – Ranger Aug 3 '16 at 16:09
• That's not a problem. It was an interesting question! – WarPorcus Aug 3 '16 at 16:20

The best thing since sliced bread.

The shield will probably stop 2 bullets, so it wouldn't save a man caught in the open against a machine gun who gets hit 5 times. Combined with a helmet it might save you from a single sniper's bullet.

Is it worth it?
Lets say that 3/4 of casualties would be from things the shield would not save you from, a barrage of machine gun fire, specially built anti-shield sniper rifles, shrapnel from grenades, artillery shells and diseases.

Even if it only prevents 1/4 of casualties, this is still worth it. The cost of training, transporting, feeding, housing and caring for a soldier, far outstrips the cost of his rifle. So yes, they would be used. Not by all armies (Russia had trouble getting its troops rifles for the first year, so they probably wouldn't go for shields for a while). Nor at all times, they would be used in combat and turned off the rest of the time.

They would decrease the effectiveness of machine guns because they can no longer just spray and hope a bullet catches an enemy. They will have to hold sustained fire on a soldier to make sure to break his shield, buying the others time to attack the machine gunner.

• About the effectiveness of automatic rifles, suppression fire is a thing. You can still spray and pray, you'll just need to spray more. – AmiralPatate Aug 2 '16 at 11:13
• @AmiralPatate yes you just need to spray each person for twice as long 1-2 hits would normaly stop them now you need 2-4 to do the same amount of damage. So you need 2x the time and ammo to do the same damage so automatic weapons are less effective. – sdrawkcabdear Aug 8 '16 at 17:06
• And every other weapon would require more time and ammo as well. However, since the firerate of automatic weapons is greater (which kinda is their thing), I'll argue it makes them that much more effective. – AmiralPatate Aug 9 '16 at 6:51

Some things that haven't quite been touched on by others:

1. Each power would have to consider their soldier to equipment ratio. Russia, more soldiers than guns, would not forgo 2-3 guns in favor of saving a soldier's life. Japan would probably not adopt the shield for ideological reasons. I'd say the three major powers to adopt the shield would be Germany, Britain, and America.

2. It's hard for me to say what Germany would do (just go with @JayGregus), but Britain and America would definitely use the shields. What everyone else seems to be implying, though, is that you just hand one of these to a soldier and say, "Use at your own discretion." In reality, the Allies were very good at information security, and would not reveal that they had these shields until the best possible moment. That moment? The invasion of Normandy. 1.3 million Allied troops landed in Normandy. 120k died. With personal shields, only 40k would die (assuming 2 of 3 "kill shots" did not kill as normal). Realistically, it would be even less, since fewer casualties means a faster victory.

More importantly, with personal shields it would take fewer soldiers to win a victory, which means you can split your force and get two victories, steamrolling your enemy before they have a chance to react.

My point is, shields would be deployed strategically and specifically for certain operations. They would not be used in the same manner as a gun where every soldier gets one. Examples:

1. Critical combat operations (Normandy)
2. Paratroopers/special operations behind enemy lines
3. Deflecting German suspicion regarding Ultra/decrypting Enigma (How did 1,000 troops defeat 10,000 troops? They were paranoid and just happened to have their shields turned on before the "surprise" attack.)
4. Propaganda: "With the new 64-10 PSG Personal Shield Generator (TM) in the hands of every single one of our soldiers victory is assured, and all our boys are coming home." Imagine the effects on morale both at home and among the enemy soldiers.

When a new piece of war technology is discovered, the question is not, "Is this, at all times, worth 2-3 guns," it's, "Under what circumstances can I deploy this to give myself a greater advantage or turn a certain loss into a key victory (or even turn the enemy's overwhelming victory into a pyrrhic one)?"

I'm going to make a attempt at answering via a shift in perspective. WWII was, in many ways a war of attrition, resources and strategies that maximized raw manpower. A simple walkie-talkie was large enough to often require a dedicated soldier to hold and operate it. Most countries devoted a stunning percent of GDP to the war effort, rationing resources and retooling a nation to produce weapons was the norm. I suggest to you that this generator in the state described is ineffective enough that some would likely be built, but most nations would rather have another rifle, than a partly-effective shield. In My Humble Opinion - you would find a secret effort to improve efficiency, but the deployment would be like that of the portable field radio or walkie-talkie...perhaps one to a unit. I could see a benefit for a forward recon, or certain other specialized functions, but most soldiers would be better served with an extra 5 lbs of rations, or 5 lb of ammo. In the event that a Manhattan-style result was a truly scalable, efficient generator, then you'd have a serious game-changer, and quite possible accelerate the development of shield penetrating weapons.

• I too think most would skip it, especially since the thing, as described, is basically disposable. If they were produced most will never see action, they would be switched on and depleted, at significant cost, for nothing. So some important people might get them, at the cost of several hundred rifles, rifles that can be used over and over. No, expensive disposable objects are way more expensive than they seem, the cost of a core would have to be closer to the cost of a bullet, or be rechargeable, to see any wide use. – Seeds Jul 28 '16 at 21:39

Since shields need to be mass-produced, and all the nations participating in WWII used pretty much all of their national production capacity, building shields in significant numbers means they need to have less of something else. So let's start by working out where small number of shields can be very useful, and then where larger numbers can save on some other kind of production.

Vey small numbers go to senior officers when they're at unusual risk, which means getting close to the front lines. The reasons for that vary between armies, but one that's always present is personal reconnaissance, when the reports aren't clear, and the commander needs to see what's going on himself, or at least talk directly to people who have.

With more shields than that, they go to recon troops, simply to increase the chance they'll come back with good information. Games, films and TV tend to skate over the "fog of war", but knowing what's actually happening and where helps enormously in winning battles.

When you start having enough to use tactically, the practices of different nations may be different. The British may well give them to commandos, whose raids were often extremely risky anyway, to let them try even more dangerous attacks. The Soviets may well give them to the crews of their Il-2 ground attack aircraft, who had horrific casualty rates, just to cut down on the number of crew they need to train. The Germans' most dangerous job was U-boat crews, where personal shields won't do any good. For US forces, the place they would help most is probably storming the beaches of Pacific islands.

For the nations that actually worry about public opinion, the lack of ability to provide shields for every man in a mass infantry attack may reduce the number of such attacks that take place.

Now, where can avoiding men being harmed save on industrial production? The obvious place is in air forces. Not all that many aircraft were lost solely because of crew casualties, but preventing those will save on aircraft production, and that consumed a lot of resources. I can't see navies getting many shields, simply because they aren't that much use against weapons used by or against ships, but inter-service rivalry may result in some getting wasted in naval service.

None of this actually transforms WWII. It was largely a war of production, and running out of people was mostly avoided.

In World War II shield generators were discovered. - by whom? I think answering this question provides different answers to your other questions.

Technology was/is very closely guarded

First off, not all countries had the technology capable of discovering something like this. So that fact alone will severely limit the players that could develop it. Even if it fell into enemy hands, two - maybe 3 - of the countries in the war had the know how to reproduce the technology. Even so, the country that discovered something like this would not share that it had it let alone how to reproduce it. Think Enigma!

Negligible Cost to Produce means soldiers stay on the battle field longer. A trained soldier with increased odds of surviving on the battlefield is more cost effective than training up a new soldier to take his place. WWII heroics are amazing to read about, especially without any kind of body armor. Imagine how those heroics would scale if everyone knew they could survive a shot or two?

Answering the question from two different perspectives

If one of the Allied forces had this technology it could have completely changed the momentum and amount of ground the Axis powers were able to chew up early on. If that force had been the US, the war could have ended much sooner and possibly without the need for a nuke.

If it was an Axis force...a lot of key battles hinged on the failure of machine gun nests. A shield could have protected those nests sufficiently to push the Allies back.

The Germans would have been nigh unstoppable and D-day may have been a huge flop.

The Japanese would have been impossible to root out of the Pacific theater.

The Italians might have actually had a bigger role.

• I appreciate your answer, and it brings up some good points! As to your leading question, to quote the original post: "Would one nation or another be more or less affected by this technological discovery?" So I intentionally didn't nail down who did or didn't discover it to leave it up to those answering. – Ranger Aug 1 '16 at 16:44
• I figure as much but thought it worth mentioning because you can't really answer the question without assuming one nation or another. I think it would be a really interesting exercise to examine the pivotal points in key battles and apply the technology to see how the outcome could/would have changed, if at all. Was a nest taken by explosives or gunshot? Was a sniper neutralized with a counter sniper or a tank? Are there any statistics on the average number of bullet wounds or sufficient records in the major battles to determine if a shield would have made any difference? – Steve Mangiameli Aug 1 '16 at 16:49
• I like imagining the concept of an earlier war end and lack of Nuke solution. then splitting the atom maybe lead to energy production rather than explosive force much sooner – Sarfaraaz Aug 4 '16 at 9:54

I'm putting this answer out with the assumption that the shield was discovered just prior to the invasion of France by Germany.

Germany - Hitler and the SS were technology geeks in a few methods and pushed things like the Messerschmitt Me 262 (jet powered aircraft) prior to many other nations...even the attempts at oversized tanks and the preference to a single massive tank like the tiger instead of multiple smaller ones. I would see little hesitation on the German side to start producing these shields enmasse, even if it came at the cost of other resources. They like to think the Aryan race indestructible, these shields would be a logical extension of that thought. They also would have invested heavily into the research on this to get it up to a tank level. If they alone possessed this shield and it made an impact on their troops attrition rates early on, they may have had the resources to fully invade Britain (troops on land) instead...with Britain knocked out, the Germans would have stood a far better chance in Russia. It also could have been given to Italian forces which may have seen them fare better in the Balkan states, freeing up additional German resources for Britain.

Britain / France - Simply put, France lacked the resources to produce these as the resources they had went almost exclusively to the Maginot line and their infrastructure. It's possible the French foreign legion would have had better access to these pillaged from their attacks. Britain was more dedicated to sea and air dominance and would likely not invest that heavily in an infantry only technology. Now if they could scale these devices to make them function on spitfires...

America - prior to their full entrance into the war, the US became the arsenal of the free world (Roosevelt coined the term) and would have thrown this item into full mass production, giving rather full access of this shield generator to it's british, french, canadian, and other allies...even Russia, but to a lesser extent due to logistics (U-boats would heavily cut into those resupplies). They also would have joined the British with attempting to scale this item up to fit onto planes and potentially tanks (if one of these could stop a tank hit, the shermans just doubled what damaged they could take from a tiger tank and would walk all over them post D-Day)

Japan - Japan wasn't as heavy of infantry user, and in many cases they were able to rely on numbers to overwhelm. Add in the relative fearlessness of their soldiers...I really doubt they would spend time manufacturing this simply for infantry. That said, a zero is a light, agile, and really hard to hit fighter that was quite fragile and when it did get hit it was almost certainly downed. Adding in a shield generator to these fighters would be a tremendous advantage...a Kamikaze is a big enough threat as is...a kamikaze with a shield generator on it would hit less like a fragile plane (destructive enough as is) and more like a heavy meteor.

Russian - I'd doubt they would move to manufacturing this device, however they could get access to it through US supplies. It'd make little difference in the long run, as they ultimately emerged victorious from the heavy infantry in-city fighting. Their manufacturing was almost exclusively tanks later in the war, and I'd have a hard time seeing Stalin not heavily invest into these shields to introduce them into tank warfare.

If this was a mid-war discovery, I would suggest that Germans would have been the ones to discover it. However just like it's jet powered planes, mammoth tanks, and v2 rocket program, it would simply be too little too late. As such, it would have no impact on WWII. At this point, it becomes a cold war contributor instead.

As far as tactic changes...in WWI and WWII, the device that claims the most kills, especially in regards to infantry and other soft targets, was artillery and mortar fire. These troops fired shells that would explode and send fragments or metal pellets everywhere, forcing troops to take cover in trenchs or other impact craters. This often left a line of cratered fields between two opposing forces and an eternal standoff. Now tanks were the ultimate tool that brought an end to these artillery standoffs, however had these personal shields been effective against artillery fire (perhaps not a direct strike, but vs a near impact) then these lines could (theoretically) been broken prior to the invent and mass production of the tank...I mean a person that could asorb two rifle hits was in his own right a mini-tank. As such, the French 'Maginot mentality' might not have fully come in to effect as these personal shields would have been seen as a counter to the defensive trenched lines (stupidly enough, this may mean that France remains much harder to conquer as they couldn't rely so heavily on the Maginot line and followed...maybe Charles Du Gaulles attempts at a modern army would have taken hold better? A lot of speculation there, but this would require the personal shield to be developed around 1935, not mid war).

There is the potential for this discovery to have changed the wars outcome however...the German seige of Stalingrad and Moscow (lesser moscow) being big ones. Stalingrad became a street to street, building to building, infantry battle. Holed in infantry were hard to get out at the best of times...having a method that would allow a German soldier to take a hit or two while charging in to break up a stubborn defensive area could have seen the Germans fully take Stalingrad. With the resources gained there, this could have seen a shift in the Nazi's fortunes in Russia (making D-Day a much more 'all or nothing' assault by the allies).

I think that's you biggest change for tactics...where city seiges often became extended period of attrition, an army with this technology could readily send in infantry expecting them to take a hit or two and still survive (allows your infantry to operate somewhat as tanks in this manner). This could have heavily increased the time in which an army can occupy a city and route out all pockets of resistance.

There are some other 'maybe effects' that could also have changed the direction of the war. The number of assassination attempts made at Hitler made him a paranoid man by the end of the war. A simple shield device that would prevent an assassination attempt may have kept Hitler in a better mental space and have him make less of the tactical errors he did. Maybe?

But I think the ultimate question that would truely effect the way WWII played out...which nation figures out the miniaturization of this device and then the logical extension to tank and fighter shielding.

• i like your closing statement's view that Hitler with the Shield would've had him a better mental state and i think that would be the biggest impact to the war end, maybe even leading to Hitler starting up somewhere else for a smaller less successful rebellion. – Sarfaraaz Aug 4 '16 at 9:47

The winning side is the one with the best logistics, strategy, tactics and equipment, in that order. There are a few points to address regardless of any historical considerations.

Equipment and tactics

It takes more to kill a guy. You may rewrite the rules of engagement to consider every soldier can soak up two bullets, even if the other side can't give a shield to everyone. That means you'll need more dakka in some way, either with more bullets (i.e. earlier development of automatic assault rifles), or bigger guns (i.e. ridiculously overpowered rifles). In the end, it doesn't give much of an edge, because you have to consider defensive and offensive technologies would compete to cancel each other.

Taking more risks because you have more protection would be ill-advised. You shouldn't expose yourself to unnecessary risks, and most soldiers don't. You could try something stupid, then trip and fall and get shredded, or your shield could just shut down for no reason. You never know.

So on the field, it doesn't change much on the issue of a battle. Good equipment can only do so much to correct a bad tactical situation. What it may change is how long the battle lasts, and how much resources it consumes.

Strategy and logistics

Let's consider everybody has the technology for a moment. Let's assume every battle takes longer and requires more ammo, more artillery, and generally more everything.

The first thing to consider is that you'll need to manufacture more of everything. That means either more factories and workers, or less of something else. That could be less sturdy equipment on the front, or that could be less fridges and radios for the folk back home. Regardless, it would have an economical impact, and that's not factoring in the shields themselves yet.

Because the shields have to be manufactured too. If they are confined to protecting a few high value people, then it won't change much regardless. If they are mass produced, then we're back to the previous problem. I can't compute the long term economics of it, but short term it would put a strain on the whole war machine.

The side with the strongest economy would still win, but the other side would possibly lose faster, which may have resulted in less lives lost on both side. Or, if it didn't shorten the war, then countries would exit the war in much worse shape. That would have influence on the flow of the Cold War and it would still resonate today, though we'd first have to predict the state of the world at the end of the war.

Asymmetry

So far I've considered the technology as symmetrically available to everyone. It probably wouldn't be nicely symmetrical that at first, though it's very likely it would eventually end up in the hands of the major players.

If one side had it first at the start of the war, it would have helped them initially. Then technology would have caught on and we'd be back to a symmetrical situation.

For Germans, that would most likely mean less casualties while taking Europe. Maybe that little extra strength would have helped then when marching towards Moscow, but in the end it wouldn't have helped their economy. I don't think there's any scenario in there which saves the Third Reich.

For Allies on the West, it may have helped them resist against the initial German push. Maybe Germans wouldn't have tickled the Soviets with a front open in the West, maybe French and British troops would have collapsed completely eventually and unable to take it back. I think that's where it would have the most unpredictable long term effect, though it could also have none at all.

For the Soviet Union, I doubt they would have been able to field it to enough troop to make any difference at all. Same for the Pacific front, it wouldn't help with all the aeronaval warfare.

If it was introduced mid-war, it wouldn't change much unless introduced at one critical moment at one critical battle. But as I mentioned before, it could have change the course of a battle by compensating for bad strategy, logistics or intelligence.

tl;dr

I very much doubt one equipment can change the course of the war and in the end it should play out about the same. What happens after the war is a different story, depending on the end state of the world, but that'd be a whole 'nother question.

This sounds quite similar to the personal shield technology used by the Goa'uld in Stargate SG-1. One particular episode examines a way around this ('The Nox' S01E08). As machine gun fire is ineffective, a bow and arrow is used, as with lower velocity this is not blocked by the shield. From the way you describe an exponentially smaller effect based on both velocity and surface area of impact, another possibility in escalating attack strategies would be to use larger projectiles... Taking this to levels of potential absurdity, a cannonball would be particularly effective due to its huge surface area. While this would obviously be impractical for the battlefield (especially since you only need a couple of extra bullets to wear down the initial 2-shot protection) it could work well for assassinating high profile politicians at public appearances.

The other effect you could have to mitigate the initial 2 shot protection would be to have synchronised snipers, 3 people ready to fire their shots at the exact same time.

Working under the assumption that these shields are set with an imprint of the space to be covered during manufacture (or maybe they have swappable cards that fit into something like a motherboard, or its a glass matrix that the field passes through to gain a shape)...

I would never use this for a full human. My torso (or torso + head) is significantly smaller than my overall body and shielding just that will protect me from the majority of lethal hits.

Other things you could shield for fun times(?), I've given surface areas where I could find it easily. I'm not crazy about military stuff so I don't have measurements for most of those things. A 'typical' human male has a surface area of ~1.9 meters, if we're including gear in his shield in your example we can round up to 2 meters:

• A 1mm thick wire, or up to something like 5mm thick. Assuming 10 meters long, surface area is .031 m² or 0.157 m². Way smaller than a human so exponentially stronger. Pair that with a larger generator and you could set it up across roads and bridges to slice oncoming tanks and vehicles in half. Could also be set up across rivers to do the same, or underwater for boats.
• Take the wire in our last example and make a net out of it. Launch the reinforced net at planes. If that seems unlikely to work, you could wait for nightfall and use large box kites to float something really light (like silk or cotton string) and then reinforce it with a shield to entangle enemy aircraft.
• On a vehicle, you could reinforce multiple small plates to create a frontal shield or something. You'd need to think about the requirements here and whether or not this would make the vehicle too heavy. My gut says that for this to be effective, the vehicle would probably be too heavy.
• On those same vehicles, you could reinforce some key areas, maybe the viewhole on a tank gets shielded glass across it or something similar.
• You might be able to shield some artillery or something so that chaff and other impacts were unable to prematurely detonate it. Probably too expensive to use on every round, but for precision rounds that need to hit it would probably help.
• I'm not 100% on how your impact reduction works, but you might be able to use it for paratroopers instead of parachutes if its able to disperse the force of a fall. Plus, it would be pretty badass to jump out of a plane, hit the ground and take off running.
• You could use shielded objects to shape blasts, something like a handheld claymore mine.
• Miniaturized shields could be used as a delay timer to prevent liquids or other things from merging inside an object. That might be a good way to contain things that you otherwise couldn't? Or would they seep through?
• You could shield some porous cloths you use to cover vents or windows to allow for more airflow in a building with a much lower cost in security
• Shields could be used to cover wooden or metal bats and things to turn them into more effective weapons
• You could shield unstable parts of weapons (like flame thrower fuel tanks) to make them less likely to be lethal to your own soldiers

My brain is a little fried this morning, but given your idea that cost increases exponentially with a geometric increase in size, the smaller the object you're covering the more efficient and effective your shield will be. So look for smaller and smaller objects to cover. Maybe also consider changing your measurement from 'surface area' to 'volume' - that would make it cheaper to cover a flack jacket than to wrap around a torso, while the current one sees them as pretty much the same.

So just to summarize the OP right quick:

• These are the personal shields from Dune, with a few extra rules.
• The batteries last 3 days, and 3 batteries cost the same as a whole shield.
• They can stop a kill shot, but not reliably.

Outfitting the troops:

One shield plus one core costs 1.33 (repeating, of course).

One shield plus two cores cost 1.66.

One shield plus three cores cost 2.

Two shield plus two cores cost 2.66.

If I am supplying my soldiers with shields, the most cost-effective way to have everyone in a state of constant readiness is to issue one shield and two cores per soldier. These shields sound expensive, so I'm probably going to go for that.

Tactical issues:

Do the shields emit light? If so, I would rather use them during the daytime to mitigate the effect. If the light is dull and staticky, I would have my troops move in close formation to camouflage one another, like zebras.

These do not sound like they are strong enough to allow soldiers to cross the machine gun fire between the trenches. The best use of these shields would be for paratroopers and special forces so they could survive a few surprises and continue fighting.

Strategy:

If the shields also conceal the person inside, I might use them to fake an alien invasion. The fake invasion as a geopolitical strategy was already being discussed by the communists at the time of WWII, so it's not implausible. Governments would waste resources on tracking down the alien hoaxes.

How the nations would be affected by the technology depends on who discovers it first. The atom bomb is the classic example of that. They would be most available to nations with factory systems.

As soon as one of these shields is captured, it becomes possible for the enemy to reverse-engineer the technology. So you only want to use it if you want your enemy to have it as well. This in turn means there are two scenarios in which you would use them at all:

1. You think you could use them to achieve a quick victory

From a cultural perspective, America and Great Britain valued life infinitely more than the other WWII belligerents (at least regarding political systems). Their populations would be most eager to mass produce the shields, but as I said, they won't do much to get soldiers out of the trenches.

Stalin would have had no scruples about using the shields to help his soldiers zerg-rush the battlefield. They would still take heavy casualties, but numbers can overwhelm.

And another thing...

Whatever technology led to the shields would also be used to create weapons. There would at least be ongoing research. The upshot is that this might have taken precedence over atomic weapons. Even if the shield technology did little to change the outcome of WWII, it could have a great impact on subsequent history.

And speaking of weapons, I see no reason why the shields would protect against gas. Large scale use of these shields could change the moral calculus of the nations. It is possible that gas would not be outlawed, or that the shields would be outlawed for encouraging the use of gas.

The previous answers in this question have all outlined the big picture, logistics, and grand strategy, so i'd like to go to the tactical level.

since the shields are capable of stopping one or two rifle rounds, and their strength increases with the surface area and velocity of the incoming projectile, submachine guns would be more effective simply because they have denser, slower, and bigger rounds, and the same goes with shotguns. Combat would be brought to closer ranges since long range sniping is largely ineffective due to the fact it takes three or more shots to kill a person.

Grenades and any type of explosive would be less effective against personnel due to the fact that the blast wave of an explosion is basically a wall of displaced particles slamming into something, this would obviously break through the shield, but the shield would absorb a good portion of the energy before going down allowing soldiers to possibly survive though severely wounded.

Shrapnel would be much less effective due to the same reason as grenades, through it might penetrate the shield due to it's low velocity, but before it penetrates the shield it would be slowed down considerably and may not penetrate the body as effectively.

Flamethrowers on the other hand would be eccellent against the shield due to the fact they are low velocity, slow, and they pump out a huge mass with tons of surface area.

Mounted machine guns would be forced to consume twice as much ammo when mowing down a massed charge of men making bayonet charges a possibility. Guns like the M2HB .50 would penetrate due simply to their mass, though would be slowed down, so countries would manufacture big low rpm machine guns like the ma deuce. Light machine guns would be very ineffective in this scenario. Antitank rifle would be a common item, and high caliber sniper rifles would be developed earlier.

War would be much more focused on close combat instead of long range standoff engagements, and this might lead to weapons like gyrojets being perfected and fielded.