Can a super-governmental military body like this work?

Question

Setting: In my conworld there is a huge region (let's call it the Midlands) spanning from the northern borealis to the wide green pastures further south, of the northern continent, which is not one single country but rather a collection of dozens of states ranging from more utilitarian ones (e.g. big guilds) more centrally situated, to small kingdoms and duchies along the region's borders.
It is entrenched between two bigger countries claiming most of the area in the northern part of the world. The Western Empire in the west; and the Eastern Reich in the east.

The territory of the Eastern Reich though consists mostly of barren land which, although rich in minerals, ores and crude oil, is mostly infertile and thus they seek to possess the more fertile lands to their west (the Midlands).

A Western Empire
G Free Regions
H Eastern Reich
J Southern Lands
K Midlands (Coalition Territory)
L Border Lands

1 Equatorial Belt    | Saltwater
2                    | Saltwater
5 Northern Polar Sea | Saltwater
6                    | Sweetwater

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History: At some point in time, an Alexander the Great-esque character rose to power in the east and rallied an army behind him with the goal of *making these greener lands available to our glorious Reich (back then nothing more than a bunch of smaller kingdoms, claiming the more fertile spots and hot springs along the mountain ranges).

When news of this rallying reached the west, the states of the Midlands eventually reached a point where they signed a contract and pooled together resources and their current individual armies, police forces, etc. to form what is called the coalition Military Force (from here on referred to as the Coalition). Thanks to this act they managed to fight back the first wave of attackers by having troops from all over the Midlands fortifying the eastern borders.
This collection of forces in turn managed to throw back the attackers long enough to give the Coalition the time needed to organize their new forces and set up a permanent block along the border, which continues to hold off the occasional raiding party from the east to this day (and further...); putting both parties in a cold-war/stalemate situation.

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Situation/Environment: The inner states of the Midlands don't have the typical concept of borders. The lands mostly belongs to families and to guilds, the latter of which tend to buy and sell land where profitable; So borders in these areas are mostly informal. This is no issue because the whole system grew up to be that way (due to the way the early tribes/nomads in the area were organized and working with each other).
The outer states tend to be influenced more by the surrounding big countries and thus some have organized themselves in duchies and smaller kingdoms.

While the duchies and kingdoms to the east of the Midlands enjoy similarly rich pastures and amounts of resources, it is the center of the Midlands that really profits from the region and they way they are set up, there are no such things as tolls and other things that hinder free trade there and thus these states are comparatively rich.

The concept of the Coalition treaty/contract stems from the historical background that the families in these areas would usually band together to achieve this or that (culminating in the formation of guilds and states).
The Coalition Treaty itself consists roughly of the following parts:

+----------------------------------------------------------+
|           The Coalition Treaty, of xx/xx/xxxx            |
|          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~           |
|                                                          |
| This Treaty shall serve as a foundation for the creation |
| of a super-governmental military body. The Signees of    |
| this treay shall receive the following rights and obli-  |
| gations.                                                 |
|                                                          |
| > Each Signee shall receive full military support in ca- |
|    se of an attack stemming from outside or inside coa-  |
|    lition territory                                      |
|                                                          |
| > Each Signee shall disband any state-owned military     |
|    forces immediately upon this treaty's inuring         |
|                                                          |
| > Each Signee shall disburse an amount of money relative |
|    to the richess of their lands,                        |
|    the size of their population,                         |
|    the safer they are from being invaded                 |
|                                                          |
| > Each Signee shall be able to disburse additional funds |
|    in return for military services such as but not only  |
|    - police forces                                       |
|    - guard forces                                        |
|                                                          |
| > Each Signee shall provide a pool of potential recruits |
|    from which to conscript additional forces should they |
|    be needed                                             |
|                                                          |
| In return the created body shall have to organise itself |
| and provide services as best as is possible within the   |
| limits of the provided funds                             |
+----------------------------------------------------------+

The Coalition therefore is basically a private army catering exclusively to the needs of the signees of the Coalition Treaty. It possesses military bases and other assets in most of the signee states. Logically it has to buy things such as provisions and material, weaponry, etc., a whole industry catering to the needs of this huge body will subsequently sprout in the Coalition territory and provide jobs and ways to shift funds back to the signee states.

Now why would they band together against a force that only seems to threaten the easternmost duchies/kingdoms (which themselves anyways chose to abandon the traditional ways for a more eastern approach) and why would the center states even consider the idea which obviously will conclude in bigger expenses for them than so far?
That is easy (mostly), easy: At the convent where most of the states gathered, the point was made that if the easternmost states/duchies/kingdoms fall, there is even less stopping the east army as it would gain a favourable position for annexing the rest of the Midlands. Thus the rich central states have a reason to back something that obviously means higher expenses to them than so far.

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Question: Can a body such as the Coalition Military Force work in the described environment? And what issues that I failed to address/addressed incorrectly make it not work?

Answer 1

Two historical examples come to mind here.

The first example is the Delian League, which has been alluded to in other answers. Formed by Athens as a reaction to the Persian Wars, the Delian league had various maritime powers band together and pool ships and funds to protect the league and the rest of Greece from any attempt by the Persians to invade again. Very soon, the Athenians simply requested money from the other league members, who were happy to oblige for the most part, since owning a navy is very capital and labour intensive. However, when Athens decided to take full control of the League's treasury, the other members discovered that not having a Navy also means not having a vote.

Athens became an Empire in all but name, and the fear of Athenian Power lead to the Peloponnesian Wars.

During the 1400's, Italian City States tended to alternate between citizen militias and hiring professional mercenary companies (Condottieri). The Condottieri quickly discovered that they could play various parities against each other, accept payments to not participate in wars or switch sides and otherwise make planning difficult to impossible for the City State authorities (or even overthrowing them if they didn't pay up according to the terms of the contract)

So the essential point is that the hand that holds the sword eventually becomes the hand which holds the gold as well, and also the whip hand giving the orders. In your scenario, the central principalities will quickly discover that what seems to be an unrooted mercenary army is now calling the shots, and their tax revenues are not being spent for the benefit of the citizens of the central provinces.

How this plays out in the end is probably similar to the end of the Italian city states. Weakened by constant internal divisions and shifting alliances, they were unable to present a united front against foreign invaders (one reason Leonardo da Vinci ended up in the French court, for example). The coalition army, not being "rooted" and existing on tax contributions from a disarmed population, becomes predatory against the very people whom it is supposed to protect, and falls apart when directly challenged by an outside force.

Answer 2

I see an analogy with the alliance of Greek city-states in the Persian Wars (499 B.C. to 449 B.C.). That also was a military alliance formed to fight off a foreign invader -- the Persians -- which was much too powerful for any one Greek city-state to resist. Otherwise, the Greeks were a pretty fractious bunch... as was demonstrated not long afterward in the Peloponnesian War (431–404 B.C.). The lack of clear borders between States, which you describe, also seems to fit the city-state model.

The only real problem I see, which user58697 already pointed out, is your stipulation that the States forming the alliance would disband their own military forces. That would be equivalent to surrendering sovereignty... but the entire purpose of forming such an alliance would be so the individual States could preserve their sovereignty. So, not gonna happen.

The alliance of the Greek states against Persia lasted little longer than the threat did. Likewise, I doubt in your scenario it's realistic for the alliance, or confederation or whatever you want to call it, would last very long once the immediate threat was defeated.

So to make your scenario work, the external threat must be something that has to be repeatedly fought off. That would create a long-term confederation, which in time would perhaps grow into something more (as the original Confederation of the United States soon became a Federation). Perhaps there's a more powerful empire in that direction, one that has a hard time extending its reach to the lands in question, so doesn't invade often... but when they do, the military threat is formidable. I can think of at least one historical precedent for that: China (or more specifically, the Mongols) vs. Japan. There were two major Mongol invasions of Japan, but both failed.

Answer 3

Gonna answer your two questions in reverse order.

The main thing I'd say you have left to address is how the CMF is structured.

Who gives the orders? It's outside any sort of government, so it would have to have an internal command chain (democracy doesn't really work when it comes to heat-of-the-moment decisions), but how is that originally established, before the CMF is well-established and they can promote people based on merit? Do the people contributing the most get to lead? Do the people closest to the conflict (with theoretically the most experience) get to lead? Who decides promotions, anyway, especially into the top leadership positions? The larger, more powerful states likely aren't going to like the idea of someone from a smaller/weaker state leading the armies, and/or would want their own families to be in safer positions, so what sort of checks would be in place to prevent bribery and corruption?

As far as it actually working.... I can see it working in the short term. But in a few generations, I can see the families of the center states getting complacent, wondering why they're paying and sending their children to fight against this "phantom threat" that isn't actually threatening them.

Then there's also the problem of the CMF being the only military power in the West. What's to stop some ambitious CMF leader from seizing power (the analogous Julius Caesar to OP's Alexander)? It would certainly happen eventually, once the CMF starts to realize that they're the only ones with the weapons, so there's no point in paying for services anymore when they could just take over and get things for free.

Answer 4

Participants shall not disband their own forces. There must be something to balance the CMF. The Treaty shall have provisions similar to Second Amendment (as in well organized militia and the right to bear arms).

The overall structure of CMF seems to work best if the Eastern states contribution is mostly military, while for safer Central it is mostly financial. Centrals however must be ready to mobilize their National Guards shall a full-scale conflict emerge, in which case this becomes a usual (temporary) military coalition.

In no circumstances may army be allowed to perform police duties.

PS: As of why Centrals would agree to contribute, there is a saying (attributed to Napoleon), that a nation which doesn't feed its own army will feed an alien's one.