General background story
Oster people call the area west of Ostehaar "the land beyond the union" (or imer-ast darna in Oster). It is an area with native Oster communities that refused to be a part of the old Kingdom of Ostehaar, back a few centuries before present times. They remained a rather isolated collection of town and villages, until occupied by the British during the 18th century.
By the early 20th century the British had left the land, and the nation of Eutriston captured it and positioned a garrison there. In the late 1970's, strengthened Ostehaar decided to take the area from Eutriston, claiming the land belongs to the Oster people. Atnaia decided to assist Ostehaar in this war.
Current map of North Gael
Bonallocia currently covers the area, but since it's been inactive for many days, I assume it'll soon vanish.
Map of "the land beyond the union"
Map of Ostehaar and said area
The war
The war would be a 1970's style ground-based combat, mainly between the Oster military (and its allies) and the Eutristonian garrison (and Eutriston's allies). It might involve naval skirmishes in the Eterna Sea.
No new military factbooks would have to be written for this. To simplify things, we would just list the forces we're sending to battle (for example, only the forces I'm going to attack with, and only Eutriston's forces stationed in the area - not our entire military forces).
Feel free to suggest ideas and possible scenarios.
Participating forces
Attacking side: Ostehaar, Atnaia
Defending side: Eutriston
To join either side, please post here how you want to be included in this story. Try to be as specific as you can (reason for getting involved, general size of force, etc.), and take realism into consideration. Also, keep in mind that it may affect current day relations between participating nations.
I'll limit the number of participants in the actual war to 5-6, but others can and are encouraged to participate in other ways (espionage and special operations, diplomacy, assistance to the fighting parties, etc.).