When I read that Secretary of State John F. Kerry reached an agreement on Syria with his Russian counterpart, Foreign Minister Sergey Lavrov, I could not help but think, "So the principle here might be if I shoot someone, all I need do is promise to throw away the gun within the next year, and I'm off the hook?"
This is foreign policy by public opinion, not by reasoned fact. We elect presidents so they can lead by taking decisive action and then explaining, sometimes after the act, the reason for their decisions. Whether we agree or not, this is one of the duties of the president, especially when it comes to national security, human life and/or the rule of law (in this case, international law).
In a sense, the president in this circumstance made no decision at all. At best it might be said that President Obama offered a recommendation, then punted to Congress and the public. Ultimately, the decision was made by Mr. Kerry's aimless ramblings and an opportunistic ex-KGB leader of the most powerful and antagonistic country in the world.
By that logic, Mr. Obama is clearly not a leader — and it can be argued he is merely a de facto president.