The depression didn't reach the USSR because the USSR did not have a capitalist government. It also didn't have a stock exchange and didn't trade with any capitalist governments. The USSR was also very isolated because of communism.
One of the main ways in which the United States attempted to strengthen its ties and influence with the nations of Latin America was by declaring that further attempts to colonize this area by Europeans would be met with resistance by the US--as embodied in the Monroe Doctrine.
What two empires? please specify