President Obama’s foreign policy is at a crossroads: Despite his efforts to mold his years in the White House around a U.S. exit strategy from the Middle East, for the second time in three years, the president has delayed U.S. military action in the region only to find himself with few options but to intervene later.

A chemical attack in Syria has clearly violated Obama’s red line warning to Syrian leader Bashar Assad last year that such an assault would force a recalculation of his decision to keep the U.S. military out of the Syrian civil war.

European allies are pressing Obama to mount a vigorous response while the international outrage over the attack is still fresh, but Obama has refused to act quickly and decisively even in the face of what his own administration has called compelling and undeniable evidence of the use of chemical weapons on hundreds of Syrian citizens.

Secretary of State John Kerry on Monday left little doubt where the administration stands in terms of what occurred and who is to blame, calling the attack a “moral obscenity” and accusing Assad of trying to cover it up even as he declined to offer any indication of how the U.S. would respond.

In 2011, Obama administration officials successfully pressured Russia and China not to veto a resolution authorizing military intervention in the Libya conflict, but they so far have encountered more resistance from the same countries when it comes to Syria.

Administration lawyers reportedly are crafting a legal justification for acting without U.N. approval. White House officials said the president has yet to make a decision about a military response and is still waiting for a final U.S. intelligence assessment on Assad’s reported use of chemical weapons.

The delays, however, have not made Obama’s decision about intervening in Syria any easier as nearly 100,000 residents have died since the beginning of the civil war in 2011, and the rebel opposition has yet to topple Assad alone, as the administration had long predicted they would.

While a bipartisan consensus is building in Washington for cruise missile attacks on Assad-controlled targets, Obama also is acutely aware of how war-weary Americans are after more than a decade of sending U.S. servicemen and women and resources to Middle East quagmires.

Polls show that Americans are overwhelmingly opposed to U.S. intervention, with only a quarter supporting military action if Assad had used chemical weapons on his own people, according to the latest Reuters figures.

The question now is whether Obama will make good on his red line threat. So far, he has failed to take action in the face of previous reports of poison gases being used in smaller quantities on Syrian rebel fighters and civilians. After the White House confirmed the small-scale use of chemical weapons by Assad’s forces in June, the administration pledged to help rebel groups in more substantial ways.

But key members of Congress warned about the opposition’s growing ties to al Qaeda and other jihadist groups, and the U.S. aid never materialized.

The gut-wrenching videos that have surfaced since the Aug. 21 chemical attack in Damascus are making the Syrian slaughter impossible for Obama to ignore. The images show dead Syrian children, rows of dead bodies displaying no discernible wounds, and people convulsing in their beds.

In his remarks Monday, Kerry said the images should “shock the conscience of the world.”

“[This is] human suffering that we can never ignore or forget,” he said. “Anyone who can claim that an attack of this staggering scale could be contrived or fabricated needs to check their conscience and their own moral compass.”

Kerry said there would be “accountability,” and White House officials have said a U.S. response is not a matter of if but which option to choose.

Still, the president’s spokesman remained circumspect about Obama’s decision Monday afternoon.

“What we are talking about ... is a response to the clear violation of an international norm,” said White House spokesman Jay Carney. “And it is profoundly in the interest of the United States and of the international community that that violation of an international norm be responded to.”

“But I’m not going to, you know, engage in hypotheticals about potential responses or what might occur after any response or any decisions is made about a response,” Carney said.

With more budget battles looming in the fall, Americans also will be forced to confront the heavy price tag for any military action in Syria.

Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, in a letter to Congress in late July said U.S. intervention in Syria could cost $1 billion a month each for five scenarios of U.S. involvement, including performing limited strikes; imposing no-fly zones; imposing buffer zones, training, advising and assisting rebels; and controlling chemical weapons.