Answer:
The United States asserted itself as an independent nation was through the adoption of the Monroe Doctrine. This doctrine came after its independence from the British and was a warning to other European countries to stop their interference in the country.
This was a major statement of the United States to the rest of the world in it being strong enough to make decisions which are in the best interest of the country.
Mein Kampf preached the idea Hitler”s political ideology and the future plans he had for Germany.
It benefited in numerous ways but mainly it and maybe most importantly it gave them the access to the China trade. The Pacific route was also Spain's exclusively for a certain period of time and there was also a great need for silver in China which was supplied by the Spaniards from their silver mines.
The most dramatic foreign episode Kennedy face was the Cuban missile crisis