What allows a country to expand? How does a country expand into more territory?

it was a act of seld fesnse more over it was a peace treaty between the fogein contunries.

can you attach the graph and answer options (:

on april 6, 1917, the u.s. joined its allies--britain, france, and russia--to fight in world war i. under the command of major general john j. pershing, more than 2 million u.s. soldiers fought on battlefields in france.