It is hard to exaggerate the damage to American standing and credibility in the world that President Obama did with his about-face on Syria: In the space of a few hours on Friday he went from signaling that military strikes on Syria were imminent after pro forma “consultations” with Congress to deciding that he would ask Congress to approve the strikes, even though he admitted that such authorization was not needed for him to act.

American allies and adversaries alike were baffled by the about-face. Don’t take my word for it. Just read some of their comments as reported by no less than the New York Times.

From a state-run newspaper in Syria: This is “the start of the historic American retreat.” Obama had hesitated because of a “sense of implicit defeat and the disappearance of his allies.”

From Israel: An analysis in Haaretz said “that Mr. Obama’s postponement of a military strike against Syria suggested that he would be less likely to confront Iran on its nuclear program going forward, and that in the Arab world, he would now be ‘seen as weak, hesitant and vacillating.’ ”

From China: “ ‘He doesn’t want to fight; he doesn’t know the outcome,’ said Mr. Yin [Gang], of the Chinese Academy of Social Sciences. ‘He’s afraid, very afraid.’ ”

This may be an unfair perception, but it is one that is taking root in the rest of the world, and it is not to hard to see why: There is no good explanation for the volte-face that President Obama did after he and his aides, especially Secretary of State John Kerry, spent the previous week breathing fire and brimstone about how retribution for Syria was nigh.

It is perfectly appropriate to debate whether U.S. military action is justified; there are strong arguments against (especially against the kind of tepid and symbolic cruise missile strike that Obama seems to be contemplating). But the time to have that debate is before the president and secretary of state tell the entire world that the U.S. is about to strike.

By failing to strike, and by kicking the decision over to Congress, President Obama is not signaling respect for the constitutional process, since, as he has repeatedly reminded us, he has the power to launch air strikes without formal authorization from Congress–and in fact he did just that in Libya. Instead, he is signaling hesitancy and doubt which is discouraging our allies and undoubtedly encouraging our enemies from Pyongyang to Tehran.