Inside White House, a Head-Spinning Reversal on Chemical Weapons

When President Barack Obama decided he wanted congressional approval to strike Syria, he received swift—and negative—responses from his staff. National Security Adviser Susan Rice warned he risked undermining his powers as commander in chief. Senior adviser Dan Pfeiffer pegged the chances of Congress balking at 40%. His defense secretary also raised concerns.

Mr. Obama took the gamble anyway and set aside the impending strikes to try to build domestic and international support for such action.