President Obama faces a highly skeptical public and Congress this week — and potential humiliation on a historic scale as well. The Senate will vote whether to grant Obama authorization to drop bombs and cruise missiles on Syria as a consequence of the country's use of chemical weapons, and the House will take up the question next week, assuming the Senate passes its bill. That remains a very large assumption, and Obama faces what essentially amounts to an American vote of no confidence on foreign policy that would be unparalleled in our nation's history.

For this, the president has no one but himself to blame. A year ago, Obama drew a red line on a whim, and has repeatedly failed to prepare the nation and the global community for its consequences. As a result, Obama is isolated at home and abroad.

In August 2012, the president made a surprise appearance at a White House press briefing to underscore his seriousness in deterring the use of chemical weapons in Syria. He drew a "red line" for intervention in the case of chemical weapons, telling the White House press corps that the use of significant amounts of chemical weapons would "change my calculus" on a military response.

The statement took the press corps by surprise — and as the New York Times reported nine months later, based on leaks from inside the administration, it took his advisers by surprise as well. A senior official told the Times that they had wanted to "put a chill into the Assad regime" with a boast that wouldn't force specific action later. Thanks to the "unscripted" remarks offered by Obama, though, the U.S. had set a marker and dared Assad to call Obama's bluff.

Had Obama begun building a global coalition for military intervention and support at home to strike Assad when needed, that ad-lib might still have proven wise strategy. Instead, Obama did nothing to prepare for an eventual use of chemical weapons. The May 2013 report from the New York Times followed an explicit retreat from the White House on that bluff the previous December, when the White House changed the definition of "moving around" chemical weapons to "proliferation" to Hezbollah.

The leak to the Times in May was also in answer to the lack of response to a reported use of chemical weapons the previous month. Obama had an opportunity to enforce his red line in April after a series of reported chemical-weapons attacks. Instead, the State Department stalled by saying the White House needed to "establish a definitive judgment on whether president's red line was crossed." In the end, nothing happened, not even significant consultations with Congress or the international community. In fact, the White House went public with the preliminary findings to bypass Congress, according to NBC's Chuck Todd, and then did nothing at all.

Flash forward to August 21, the anniversary of Obama's red-line comment. Evidence of a significant chemical-weapons attack arose from the suburbs of Damascus, with several hundred dead and perhaps another 1,000 people afflicted, many of them women and children. Within days, and without consulting with Congress, Obama decided that the US. had to answer this event with military strikes against the Assad regime, before U.N. inspectors even finished their inspection, let alone their report. Within days of that decision, Obama then reversed course and decided to ask for congressional authorization, even while Secretary of State John Kerry argued that the president didn't need approval for strikes against a country that posed no immediate or imminent threat to American national security.

That was not the end of the disarray; indeed, it was just beginning. Kerry tried to argue that bombing another country didn't amount to an act of war as long as we didn't land troops on the ground, which he called "war in the classic sense." At almost the same time, Kerry suggested that troops on the ground might be an option to engage the Syria hawks who want to impose regime change on Damascus, and then abruptly dismissed the idea when challenged to reconcile the contradiction. Obama then denied he'd set the red line at all, claiming that the world had set it through conventions barring the use of chemical weapons. But those conventions require global diplomatic action and then U.N. enforcement, not American unilateral military action.

As President Obama prepared to make his case on every television network and in a speech directly to the American people this week, the disarray continued. Kerry, in another attempt to argue that bombing Syria wasn't an act of war, promised an "unbelievably small" attack, which would presumably still deter Assad. In the same press conference in London, Kerry inadvertently suggested a diplomatic solution that would involve having an international force secure Assad's chemical weapons — a suggestion that the State Department tried desperately to reverse. Instead, Russia agreed to quarterback the effort and Syria announced its support for the proposal, which might have been a diplomatic triumph for the U.S. if (a) we had demanded this a year ago when President Obama set the red line, and (b) the Obama administration had thought to at least try it first before demanding approval for military strikes on Syria. Meanwhile, Obama's arguments for military strikes were already taped by the networks, and his White House address on the eve of the anniversary of 9/11 and Benghazi remained on the schedule.

If any foreign policy deserved a vote of no confidence, the White House's handling of the Syrian crisis tops the list. Voters apparently believe so as well. In a CNN poll published on Monday, 59 percent of Americans opposed potential congressional authorization for military strikes, including majorities in every demographic. A Pew poll put that figure at 63 percent.

Obama and the White House argue that the strikes have to take place to maintain American credibility in the Middle East, as a further deterrent to Assad and to the Iranians who support the regime and want to develop nuclear weapons. The disarray displayed by the administration has done more damage to that credibility than a measured approach within the global conventions ever could have done. A congressional rejection of military strikes would prove less humiliating in the long run than anything we've seen from the White House over the last year. Based on what has already transpired, who could possibly have any confidence in the Obama administration's handling of actual military intervention?