Men stand along a crater caused by what activists said was a Russian airstrike in Latamneh, Syria, on Friday. (Ammar Abdullah/Reuters)

AMERICANS AND Europeans are seeing the results of four years of U.S. disengagement in the Middle East. A country destroyed, with half its people displaced from their homes. Hundreds of thousands of refugees besieging an unready Europe. And now, Russian warplanes bombing U.S.-allied forces as American officials alternate between clucking reprovingly and insisting bravely that Russian President Vladi­mir Putin will be sorry in the end. That is a tempting dream, but it represents the same wishful thinking that got us here in the first place.

How did we get here? It’s worth recalling, briefly, a bit of history. When Secretary of State John F. Kerry took office at the beginning of President Obama’s second term, he argued that Syria could be saved only with a political solution: The United States did not want to repeat its Iraq mistake and chase President Bashar al-Assad and his regime out of office with nothing to take their place. But, he said, the regime would not negotiate seriously until its opposition was strengthened, and so Mr. Kerry and others in the administration favored U.S. assistance, including training for the rebels, protection of safe zones where they could begin to govern without fear of Mr. Assad’s barrel bombs and chlorine gas, some arms and other military aid.

Mr. Obama would never agree; or rather, sometimes he agreed, and failed to follow through, and sometimes he just said no. Mr. Kerry was left with no option but diplomacy, in particular begging Russia and Iran to bail him out. This was always based on a fantasy: An essential plank of the Putin ideology is to protect dictators wherever he can. Anything less could give his own people dangerous ideas. He toyed with the Obama administration for a few years and then took matters into his own hands. Of course he is not in Syria to destroy the Islamic State. He is there to save a dictator, while protecting Russia’s naval base on the Mediterranean coast.

It is tempting, as we say, to believe that this must end badly for the Russians. “They want this quagmire? Welcome to it!” And perhaps they will be bogged down and targeted at home by terrorists; we can’t foresee the future. Certainly U.S. officials are right that Russia’s actions will not be helpful to Syria. More and more Sunnis, seeing they have no protection elsewhere, will gravitate to the Islamic State as their only refuge. Radicalization will increase, and the prospects of a negotiated solution will recede.

But that is not Mr. Putin’s concern. Already he has forced the West to change its tune on Mr. Assad; he has to go, but “it doesn’t have to be done on day one, or month one, or whatever,” Mr. Kerry now says. Europeans, desperate for anything to end their refu­gee crisis, are wondering whether Russia might not offer a better bet than the United States. Mr. Putin has broken out of the isolation Mr. Obama tried to impose for Russia’s illegal dismemberment of Ukraine. And Russia’s lesson is not lost on people all over the world who might attempt to democratize their authoritarian countries: You cannot count on the United States, but your dictator can count on Russia.

Two things always have been true about Syria. First, there have been no good or easy policy options; and second, with time and inaction, the options become worse and harder. Today there are still things Mr. Obama could do: Carve out safe zones. Destroy the helicopter fleet Mr. Assad uses for his war crimes. Provide aid to the battle-hardened force of 25,000 fighters, mostly Kurdish, that, as Post columnist David Ignatius has reported, is ready to attack the Islamic State’s capital of Raqqa. As Russia deploys more air defenses to bolster the Assad regime, some of these options, too, will narrow and disappear. What will not disappear is the humanitarian catastrophe Syria represents, nor the national security threat emanating from its ruins.