BERLIN — At dinner the other night, perusing the debacle that is Syria, a German friend observed: “It’s the post-American world — and that means chaos.” We were joined by John Kornblum, the former U.S. ambassador to Germany, whose verdict was similar: “What you’re seeing is the steady break-up of the postwar system.”The United States, through its secretary of state and president respectively, promises an “unbelievably small” military response to the gassing of hundreds of Syrian children by President Bashar al-Assad, then vows that “the United States military doesn’t do pinpricks,” and then backs away. Britain abandons its closest ally at crunch time. The European Union is divided, Germany silent, France left dangling, and NATO an absentee. If there are other pillars of the trans-Atlantic alliance, do let me know.

Vladimir Putin steps into the Western void, spurred by an off-the-cuff remark in London from John Kerry (that he himself seemed to dismiss), and suddenly Assad’s Syria promises to give up to international supervision the chemical weapons whose existence it has previously denied.

A war-weary America clutches at this Syrian straw and defers to Russian mediation; a congressional vote on military action that President Obama seemed set to lose is indefinitely postponed; Obama uses an awkward prime-time address to say dictators “depend upon the world to look the other way” when they commit atrocities — and so he will, well, pursue a “diplomatic path” for now.

“The ogre,” as W.H. Auden wrote, “does what ogres can.” It is safe to say that no ogre the world over, least of all in Damascus, trembles today.

There are always rough edges in a crisis. But message discipline on Syria from the careening Obama administration since Assad’s devastating chemical weapons attack more than three weeks ago has been hard to discern. As another former U.S. ambassador noted, “If these guys were building cars, you would not buy one.”Now it just may be that Assad, who traffics in deception and slaughter, will hand over his sulfur mustard and all the rest, sign the Chemical Weapons Convention, shake hands with Putin and get back to his civil war, having pocketed Obama’s statement that, “I don’t think we should remove another dictator with force.” It might even be that Putin, having made an impassioned case for international law, will rise above his Libyan hangover and allow a Western-drafted Security Council resolution framing the deal under Chapter 7 of the United Nations Charter, which allows for military intervention in the event of Syrian noncompliance. (Without this, any agreement is meaningless.)If this occurs Obama will have dug himself out of the hole he dug himself into and something will have been gained.

I am more than skeptical. The scramble reminds me of the farce during the Bosnian war that involved the Serbs handing over “all” their heavy weapons to the United Nations to avert air strikes — and then resuming their bombardment of Sarajevo.

A State Department spokeswoman had it right when she initially described Kerry’s proposal as purely “rhetorical,” because “this brutal dictator with a history of playing fast and loose with the facts cannot be trusted to turn over chemical weapons.”The hesitancy since the chemical attack has highlighted a lack of U.S. leadership throughout the Syrian conflict. The just cause of rebels fighting the 43-year tyranny of the Assad family was never backed by arming them; and when Islamist radicals moved into Syria, their presence was used to justify the very Western inaction that had fostered their arrival.

The sight of a president who draws a red line on chemical attack and then says “I didn’t set a red line” (the world did); who has Kerry plead a powerful case for military action only to stall; who defers to Congress but seems happy enough with Congress ambling back into session more than a week later; who notes that for “nearly seven decades the United States has been the anchor of global security,” and then declares “America is not the world’s policeman” — the sight of all this has marked a moment when America signaled an inward turn that leaves the world anchorless.

The president has reflected the mood in America. Almost two-thirds of people surveyed think the United States should not take a leading role in trying to solve foreign conflicts, according to a recent New York Times/CBS news poll. Principle backed by credible force made the United States the anchor of global security since 1945 and set hundreds of millions of people free. Obama has deferred to a growing isolationism. His wavering has looked like acquiescence to a global power shift.

In Berlin, which survived as a free city because of a U.S. red line, the change has been noted. It has also been noted in Tehran, Moscow, Beijing and Jerusalem.

A letter this week on the Syrian gassing to the German news magazine Der Spiegel from Dr. Tewes Wischmann of Heidelberg read: “We will be asked by our children what we did against this mass murder, as we asked our parents about Nazism. We will then lower our eyes and have to remain silent.”