Answering that question isn't simply done. President Roosevelt sought approval of Congress in December 1941. Other presidents, as Foreign Policy magazine has written, have taken the opposite approach.
The magazine writes:
"There is ample precedent in recent history -- and with precedent, the more recent, the more authoritative -- to support the view that the president does not need a joint resolution of Congress, much less a declaration of war, in order to initiate hostilities on a valid constitutional basis. The rescue of the Mayaguez (Ford), the Iran hostage rescue attempt (Carter), the invasion of Grenada (Reagan), the intervention in Lebanon (Reagan), the invasion of Panama (Bush), the air attacks on Serbia (Clinton), and the cruise missile attacks on Afghanistan and Sudan (Clinton) are all recent examples."
The Nation magazine has also written on the subject this week and highlights FDR's actions before World War II. Both stories are worth reading as we wait to see what happens on Capitol Hill.
-- Phillip Tutor