Answer:the Checks and Balances system.
Explanation: the Checks and Balances system.
To fight and gain land and supplies. And more space for the troops
Before Polk, the United States and Mexico had boundaries along the Rio Grande River. Texas and Polk claimed that America's southern border ran down to the river south of the United States' positon back then. They had a war, but Mexico lost and U.S kept expanding.
Hope this helps!
I think the answer might be League of Nations. I hope this works for ya!
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