Irredentism
"Irredentism is any political or popular movement that seeks to claim/reclaim and occupy a land that the movement's members consider to be a "lost" territory from their nation's past. Wikipedia"
They welcomed the Americans and fought alongside them.
The main reason why the Framers of the Constitution included the amendment process was because "A.)They wanted to provide a way to change the Constitution as the country changed," since they new that a "rigid" document would lead to disaster.
Southeast Asia. This is mostly because of the war