a great idea! Might steal that 
No problem.

There is historical and fictional inspiration for such scenarios: Portuguese sailors introducing arquebuses in Japan in the 16th century, traders selling weapons to Natives in North-East America in the 18th C., adventurers trying to use local tribes elsewhere (The Man Who Would Be King) etc.
If there are more than two players there could be different views and objectives in each side: disagreement amongst the invaders (one just willing to invade and another trying to negociate with locals) and also between the defenders (one just willing to resist and another willing to negociate) etc.
Um, just saying.

Too many scenario and projects, not enough time!
