What clause(s) expanded the power of the executive branch, especially relating to foreign policy?

Under the official power, the president can fire authorities in the official branch, make concurrences with remote countries, or take crisis activities to spare the country, despite the fact that none of these forces are indicated in the constitution. the official power will be vested in a leader of the unified conditions of america.  

From the president provision stream forces to utilize military power and gather remote knowledge. Presidents additionally draw on statutory specialists. Congress has passed enactment giving the official extra specialist to follow up on explicit outside strategy issues.

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.