Which statement best describes the united states' changing role in the world during the twentieth century?
it changed from a great power into an isolationist nation, much like japan.
it was vastly richer, larger, and more powerful than it had been one hundred years before.
its losses during the war of 1812 substantially weakened its power for the next hundred years.
its strict economic controls resulted in a widespread return to mercantilism.
it became a military superpower in the world but lacked a strong economy.

The last choice "It became a military superpower in the world but lacked a strong economy."

Explanation:

the right answer is the end of world war ii

after the end of a global wwii all the nations involved, in an attempt to create an organization to maintain world peace. this agreement would work settling international disputes via negotiation and arbitration instead of leading the issues escalate to another war.

julius caesar turned the roman republic into the roman empire by coming in and taking the "dictator" role during the time of a civil war (elites vs lower classes) winning battles and reputation, then declaring him dictator for life

hope this : )