By FOUAD AJAMI

The ordeal of Syria has been a rebuttal of what the diplomacy of Barack Obama once promised and stood for. It is largely forgotten now that Syria and Iran were the two regimes in the Greater Middle East that Mr. Obama had promised to “engage.”

Back when he was redeemer in chief, Mr. Obama had been certain that the regime in Damascus would yield to his powers of persuasion. He cut Damascus a wide swath, stepped aside when the Syrian regime all but laid to waste the gains of the 2005 Cedar Revolution in Lebanon, assassinating and terrorizing its way back into its smaller neighbor.

When the storm that broke upon the Arabs in early 2011 hit Syria, the flaws of the Obama approach were laid bare. It took five months of hesitation and wishful thinking before Mr. Obama called on the Syrian ruler to relinquish power. That call made, he had hoped that the storm would die down, that the world’s attention would drift from the sorrows of Syria.

But the intensifying barbarism of Bashar al-Assad’s regime, the massacres and atrocities have given Mr. Obama nowhere to hide. A United Nations report recently determined that children as young as 9 have been subjected to “killing and maiming, arbitrary arrest, detention, torture and ill-treatment, including sexual violence, and use as human shields.”

Associated Press/Edlib News Network ENNSyrians gather around a U.N. observer vehicle in the northern town of Kfar Nebel, May 29.

For months the abdication over Syria sought cover behind the diplomacy of Kofi Annan, the designated envoy of the Arab League and the U.N. But Mr. Annan has conceded that his diplomacy has been helpless before the violence. A regime built for a crisis such as this, fine-tuned by a ruling family and a dominant sect over the last four decades, had nothing but contempt for U.N. diplomacy. “And how many military divisions does this Mr. Annan command?” was, doubtless, the sentiment of Assad’s henchmen.

Indeed, the U.N. monitors there came under attack last week. En route to the besieged town of Haffa, their convoy was shot at and set upon by thugs throwing stones and wielding metal rods. U.N. chief peacekeeper Hervé Ladsous described the situation on the ground well when he said, “Keeping a peacekeeping force when there is definitely no peace to observers—that summarizes the situation.” Last Saturday’s official suspension of that peacekeeping effort is an acknowledgment of that glaring reality.

Those hamlets of grief that came to fame in recent days, Houla, Qubair, sites of cruel massacres, tell us that the Assad regime is convinced that no outside intervention is on the horizon. Syria is in the midst of the sectarian war Assad sought all along. He has trapped his own Alawite community, implicating it in his crimes. In the recent massacres, Sunni areas have been sacked by neighboring Alawi villages. The army did the shelling, then the Alawi neighbors closed in and did the killing—women and children shot at close range, corpses burnt, crops and livestock and homes destroyed.

This sectarian slaughter is what the Assad tyranny had wrought, and what the abdication of the democracies had fed in the cruel, long year behind us. In this ordeal, there was always another appeal to the Russians. We ascribed to them powers they did not have because their obstructionism was useful. The Assad regime, long a Russian asset in the region, is a variation on the Russian autocracy of plunder and terror. By all accounts, there is glee in Moscow that Washington and the NATO powers pay tribute to Russia.

And why would Russian strongman Vladimir Putin do us any favors over Syria? Despite Mr. Obama’s inane announcement Monday at the Group of 20 summit that he and Mr. Putin “agreed that we need to see a cessation of the violence,” Russia has come to believe the Syrian regime is engaged in a war with Islamist radicals much like its own against the Chechens. Grant Mr. Putin his due; the way he brushed aside Mr. Obama’s pleas on Syria should lay to rest the fantasy of a Russian compromise.

Last week U.S. Secretary of State Hillary Clinton announced that Russian attack helicopters are being delivered to Syria and warned that this “will escalate the conflict quite dramatically.” It’s a sad fact that the Obama administration isn’t willing to see in Homs and Jisr al-Shughur reflections of our own belief in liberty.

Why can’t this president simply state the truth, that the Syrian people are rising out of decades of servitude and fear to bid for a new political life? On a recent visit to Syrian refugee camps in Turkey, ordinary Syrians asked me why the U.S. is not more concerned with their fate. But they ask and anguish less and less over Mr. Obama, knowing that their sorrows have not stirred his conscience.

The Obama policy rests on a blissful belief that Syria will burn out without damage to American interests, and that the president himself can stay aloof from this crisis. By his lights, he has kept his compact with his progressive base—he liquidated the war in Iraq and has kept out of the conflict next door in Syria. It suffices that Osama bin Laden was killed, and drone attacks on al Qaeda continue apace.

The wider forces at play in the Greater Middle East do not detain this president. His political advisers have not walked into the Oval Office reporting that he’ll win re-election if only he takes a more assertive stance toward the dictators in Damascus or Tehran. The world can wait—Syria has twisted for 15 months, and it is only five months until the election. And the amazing thing of it all is that Mr. Obama’s Republican rival, Mitt Romney, cedes him the foreign policy domain, allowing him to pose as though all is well in the world beyond our shores.

Mr. Ajami is a senior fellow at Stanford University’s Hoover Institution and the author most recently of “The Syrian Rebellion,” just published by Hoover Press.