In the century XIX the Americans used the diplomacy of the gunboats.
In the first half of the century XX used the diplomacy of the bombings to the German and Japanese cities.
In the second half of the century XX used the diplomacy of the ballistic missiles, atomic bombs, coup d'état and of the dictatorships imposed the most fragile countries.
In the beginning of the century XXI USA uses the diplomacy "we won the Cold War and, therefore, the world is ours and who is not with us will be against us."
The Americans run the at full speed believing that they has an immense plain for the front. They don't notice that they are in the border of the hole that they had built in a recent past. If the world has to choose among living together with Chinese and Russian (on a side) and Americans of the other, the Americans don't have to smallest survival chance.