That is false. Congress does not need the help of the president. In fact, the President has no authority to regulate trade, only Congress does.
Probably nuclear because as seen in the bombing of Hiroshima & Nagasaki, both cities were leveled with ruins of building left.
In 1823 U.S. President James Monroe proclaimed the U.S. protector of the Western Hemisphere by forbidding European powers from colonizing additional territories in the Americas. In return, Monroe committed to not interfere in the affairs, conflicts, and extant colonial enterprises of European states.