What are things to consider and keep in mind when making a heavily fortified and militarized border?

Question

Here are some maps for reference

For some context, in my world, from 2030-2040, an event known as the Great Collapse saw the human race pushed towards the brink of extinction due to Unidentified Colossal Organisms/UCOs rising up from their ancient hibernation in order to rampage and cause chaos and destruction across the planet, leading to the deaths of billions along with the collapse and even extinction of entire countries, peoples, and cultures.

Out of the over 350 individual UCOs that rose up, the largest, strongest, most destructive, and most powerful of them all, Godzilla (who stands at over 500 meters tall), was directly responsible for directly killing over 850 million humans on all seven continents while also being directly responsible for the collapse of tens of countries along with battling and killing dozens of other UCOs that challenged Godzilla. It doesn’t help that Godzilla is the only known Apex-class UCO to have been discovered, making him the top of the planet’s food chain.

Anyway, Godzilla’s territorial realm extends across the entire Pacific Ocean/Pacific Rim and includes large swaths of land in Asia, Oceania, North America, and South America. In the United States of North America, after Godzilla ravaged what was once the Western United States of America and British Columbia (which now form the Godzilla Continental Exclusion Zone) and forced the mass evacuation of over 50 million people, the USNA military fortified the Rocky Mountains and established the Western Defense Line, the most heavily fortified and militarized border on the planet stretching from Fairbanks, Alaska down to Phoenix, Arizona, in order to defend against Godzilla and any other UCOs in the Exclusion Zone.

My idea so far involves the Western Defense Line having over 60,000 troops in total. The WDL has 12 massive fortresses call Battle Stations lining across the entire Defense Line in strategic locations, with there also being eight Command Battle Stations that oversee a particular sector of the WDL (the Battle Stations and Command Battle Stations look like the Shatterdomes from Pacific Rim). Each Battle Station has 3,000 troops stationed there and is fully capable of being self-sufficient, with each Battle Station having their own ground and logistics units and a dedicated air wing. Each Battle Station is also equipped with two Massive Ordnance Projectile Cannons, which are the largest artillery pieces ever created capable of annihilating entire city blocks and shooting at a target 60 miles away.

But what else should I keep in mind when creating heavily fortified and militarized borders? What should I add and/or avoid doing?

Answer 1

The Maginot Line worked as designed. It wasn't enough.

In the modern age, the purpose of fortifications is not to win or to hold out, it is to allow a small force of defenders to delay the enemy and to buy time for offensive action elsewhere.

• Tactically, defensive positions allow a force to inflict greater casualties than it suffers, which means that the attacker has to concentrate a superior number of troops. For mechanized war, a ratio of 3:1 or higher is in the literature.
• Strategically, standing on the defensive means that the attacker can decide when and where to attack. He will be able to achieve superior concentrations locally.

Why defend, then? Either because you've just about lost, or to free more of your own troops. The much-maligned Maginot Line did stop the Germans from breaking through where the line was, but the Germans just went elsewhere. It was the failure of the French mobile forces to stop the Germans which lost the war, not the static defense of the line.

That being said, your numbers don't make sense. 20 bases with 3,000 troops each are 60,000 fortress troops, about as many as in two or three divisions. If the US still can build fortresses, they should have way more than two divisions left.

A cannon range of 60 miles rivals what the most modern artillery can do today, but it means 12 fortresses can only defend a 1,440-mile circumfence. That's not enough to hold the Rockies.

There used to be artillery firing nuclear shells. They could level more than just a city block. For that matter, look at modern rocket artillery.

So if you want to tell an adventure story with giant monsters, go for it. But don't get nailed down on details.

There are "many" fortress bases. Your characters don't know how many, they know theirs, they know the ones on their right and left flank, they know the one where their old buddy was reassigned. Or maybe the details are all classified.

Answer 2

You Don't Want Walls, You Want Bait

Sure you want to have a 20ft high steel wall with a 100ft wide 40ft deep trench facing the exclusion zone to keep out the low-grade Kaiju. Or at least a fence to ward off humans who accidentally stray to far west. You might even want some strategically placed strongpoints for specialist troops/machines to sally from in the event a mid-grade Kaiju gets frisky. But what you REALLY want (Given that Godzilla is essentially unkillable and the high-end kaiju probably only slightly less invulnerable) is a way to get the Tier 1 Kaiju to GO ANOTHER WAY.

So you want Bait. Tunnels under your lines that stretch deep into the exclusion zone that are far to small for any sort of Kaiju, but which on short notice can pop out something that interests the Kaiju. The Bait then heads screaming in the direction opposite of your walls/civilian centers. If you want added spice, maybe have it head towards another known Kaiju in the hopes the monsters will kill each other off. These Bait machines also need to have SOME sort of Kaiju nourishment, so they don't end up getting viewed as inedible and eventually ignored.

Why tunnel-deployed? You don't want the Kaiju to view the Wall/end of the zone as a source of food. Thus you need some sort of underground system where the Bait inevitably appears BEHIND any Kaiju that hits X location. You'd want literally thousands of such tunnels so the appearance of Bait could be deemed random and you don't just have Kaiju "camping" the tunnel exits. For the same reason they need to be as hidden as possible. This also means that there needs to be essentially wasteland between where the bait arrives and the wall. So the Kaiju thinks "man that looks like a terrible place to find dinner" and makes going towards the Wall as unappealing as possible. So they get to the edge of the wasteland, a tasty snack pops up behind them, and they think "oh yeah, there's obviously better hunting in the West."

What Nourishment? That depends on the type of Kaiju. Worst-case scenario is they're manned craft. And lets face it, they are because "Kaiju bait pilot" would be a HELL of a main character. Plus who knows how good your radio/satellite comms are. I'm envisioning some sort of ATV/mech/skimmer (tech-level depending) that carries a human crewman or two and a couple cows or a few tons of meat or radioactive elements/whateverelse a Kaiju feeds on in your universe.

The Plan Ensign Ricky is a KRV (Kaiju Redirection Vehcile) pilot, and it's his shift at Bastion 12 when a Primary Level Kaiju crosses within 50 miles of The Wall. Bastion 12 goes to Alert and Ensign Ricky mans his KRV and prays. at 40 miles to the wall the Kaiju officially enters the Redirection Zone and Ensign Ricky's KRV is launched. Tactical command has set up Ricky's KRV to appear half a mile to the Northwest of the Kaiju. The KRV appears, and sends up various flares/sirens/look-at-me devices. The Kaiju, naturally, turns. It sees the KRV, senses the meat/radioactivity/whatever inside, and pursues. Ensign Ricky now plays the dangerous game of trying to stay in front of the Kaiju and unkilled for either A: as long as possible, or B: until he reaches some arbitrary distance from the Wall far enough away that the Kaiju won't just turn around and be back in an hour. The chase might last days, it might last hours. Hell it might take weeks! (No idea on your Kaiju speed.) Eventually though the jig is up. Ricky ejects. The pod punches him clear of the Kaiju, who pursues the KRV, kills it, and feeds. Ensign Ricky now must face the treacherous Exclusion Zone and potentially other Kaiju to return home, and/or Ricky is killed by the Kaiju and his family gets a "Deeply Regrets" telegram.
(Sidenote: you could also have tunnels like 200 miles away where KRVs could dive into and escape Kaiju, but that's a whole other problem of "do the Kaiju dig after it" "do the Kaiju now 'camp" the escape holes" etc. etc. running-hopefully-ejecting-hike-back seems like the best of bad options to me at this point.)

You could also have some sort of airborne recovery teams to rescue ejected KRV pilots. But then you run the risk of a Kaiju following such an aircraft right back to the wall, which isn't ideal. Though if your Kaiju are slow enough it's a possibility. Or you may want to launch "Squadrons" of KRVs because bigger Kaiju won't be interested in "just" 1,000lbs of meat/radioactive stuff/whatever they eat.

*Addendum: Your 60 mile range "city block leveling" artillery is hugely under-gunned. An upgrade in range and/or lethality is needed if you want these to be in contention for "largest artillery pieces ever created." See [HERE] for latest super-artillery1 and even the Paris Gun in WWI was longer-ranged.

Answer 3

Things to keep in mind:

• At least 50% of your soldiers are off-duty or sleeping at any particular time. Another 10% are likely away on leave. Some small percentage are on sick-call, a few may be incarcerated. 3,000 at a base means perhaps 1200 awake and on-duty.
• 12-hour shifts wear people down after a few weeks. It lowers morale and readiness. People can do it for a year or more if they must...but they won't like it.
• Soldiers require constant training and re-training to maintain proficiency. The list of tasks to train upon can be endless, depending upon their specialty.
• It takes months to train new soldiers in the minimum tasks that they need to perform as a unit to avoid being a liability in battle. Since you don't know when an attack will happen, you might need that training pipeline going all the time to prepare replacement soldiers. Alternately you might need to train 20,000 new soldiers every summer. And all those trainers are in addition to your force at the border.
• It takes years to train new officers and sergeants, especially if you want them to be any good.Both also needs years of ongoing training. In the USA, about 20% of officers are in full-time next-level training (or teaching it) at any particular time.
• It's phenomenally expensive to train, equip, feed, house, arm, and sustain a military fighting force. It takes a vast logistical chain, an enormous industrial base. 60,000 is pretty small, but still requires warehouses full of artillery shells and fleets of trucks to haul food. Those 20,000 new conscripts (or recruits) each year need boots and uniforms. Scouts and spotters need fuel and parts for their snowmobiles and dune buggies and radios and binoculars.
• Conscripts tend to be cheaper to pay than professionals, but also tend to have more casualties, and tend to be a bit more corrupt: Your replacement demands will be higher, your logistics folks bloat up as more double-checking is needed, and your incarceration percentage bumps up a few percent.

Answer 4

Hotties in planes!

You need some characters with the perspective to tell your story. The people in charge of firing the big guns don't have that perspective and they also never work out and their skin is terrible. You need fighter pilots to fly out and look at the kaiju with their own gleaming eyes. They can help aim the big guns and satellite weapons and with their acerbic and witty reports from the front. They can volunteer at great personal risk to carry experimental weapons. They can wear skin tight futuristic flight suits. They can lose a friend to a kaiju and swear revenge. They can fly in kaiju mouths and detonate above mentioned experimental weapon - but maybe they bail out at the last minute! Holy cow!

Yes, yes: the hotties. Hotties of all persuasions but all with perfect teeth and toned abs will fly planes forward from your very stationary and boring wall and engage kaiju in all different engaging ways. Your story will write itself!