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
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.
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.
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?