Does the president defer to congress on foreign affairs?

Answer 1

Not lately. Constitutionally speaking, the War Powers Act of 1973 over then-President Nixon's veto, requires the President to consult Congress "in every possible instance" before sending troops into "hostilities or situations....." which are "clearly indicated by the circumstances." The President is also required to report any such deployments (which they just said can't be done without their prior approval) within 48 hours, and if Congress doesn't approve within sixty days, the troops must be sent home (with a 30-day extension to ensure safe troop withdrawl.) Congress may also force troop withdrawl from any where, at anytime by simple majority vote; however, the Supreme Court overruled this provision in 1983, stating that only a joint resolution by Congress, subject to Presidential veto, was the only means to force troop withdrawl. The WPA didn't perform as expected, as Presidents didn't always feel like notifying Congress before the deployment of troops which would start the 60-day timer, but it remains in force.