Diaspora means the dispersion of the Jews across the entire face of the earth. In other words, it means that the Jews were scattered to the four winds of the earth. This occured when the Assyrians invaded the ten tribes of Israel in 722 BC.
Diaspora is when a specific group or population is scattered across the world in a place that is not their origin. The Jewish Diaspora (or exile) started in 515 BCE when the Assyrians forcibly exiled the Ten Israelite tribes out of their homeland. Later in history, both Jewish temples would also be destroyed.
The focus was on expansionism, the United States took little part in foreign affairs for much of the 1800s. Committed to the policy of isolationism, the U.S. declined to intervene in an independence movement in Poland when asked to do so by foreign leaders.
The purpose of treaties between the U.S. Government and Indians was to first of all keep peace between the two and give colonists permission to settle Indian land. Hope this helps!