If not good law, there was worldly wisdom in the maxim attributed to Napoleon that "The tools belong to the man who can use them." We may say that power to legislate for emergencies belongs in the hands of Congress, but only Congress itself can prevent power from slipping through its fingers.
Jeffrey A. Meyer,
Congressional Control of Foreign Assistance,
Yale J. Int'l L.
Available at: https://digitalcommons.law.yale.edu/yjil/vol13/iss1/5