Obama should announce that the US is committed to a political solution in Syria, and that his government will do whatever it can to bring about such a solution through next week’s peace conference and follow-up action. But if a ceasefire has not been achieved in the next three months, the US should work with regional organizations and all friends of the Syrian people to authorize a set of military strikes on Al Qaeda-linked forces and on the killing machine that Assad’s government has aimed at civilians.