Question

What were the main incentives for countries to seek new territories

Answer 1

The main incentives for countries to seek new territories historically is to gain political and economic power. By gaining new territories governments and empires gained new territory to fuel them economically, and also to provide international prestige and increase their power relative to other enemy states or governments. 

Answer 2

The main incentive for countries to seek new territories in the US and around the world is called imperialism. Imperialism is the practice of extending a nations power by gaining territories for a colonial empire policy. used by strong countries to gain  social political and economic control over foreign countries.