The U.S. Constitution reserves the power of foreign policy for the Executive Branch. But the founding fathers likely did not forsee the degree of connectivity the world would experience and certaintly would not think a managed fiat currency system would have any chance at achieving price stability.
The Logan act ostensibly prohibits foreign policy actions unless approved agents of the Executive Branch conducts them.
So what has the Fed done with its massive currency swap agreements with foreign central banks? The Fed has entered into commitments of $500 Billion to said banks. The point here is mission creep, where specific powers and specific restraints are willfully disregarded in the name of expedient "action".
I suppose the countervailing point is the scalability of disaster. A poker player will play much differently in pot-limit and no-limit tournemants...the risk of total loss or total disaster does indeed cause decision makers to alter their process.