This has been the year of Vladimir Putin's ascendancy. The Russian president has made Barack Obama look like a conman's stooge – a lame duck president so weak that he can barely waddle to the pond. Putin has managed to protect his client dictatorship in Syria – even after it broke one of the few taboos limiting man's inhumanity to man by using chemical weapons. He has Edward Snowden, perhaps the most damaging leaker in recent history, under the vigilant eyes of his secret police in Moscow. He has out-manoeuvred the pro-European demonstrators in Kiev and bought off the Ukrainian government.

At home, his control over the state and civil society is so complete that he can afford to play the merciful tsar and release dissidents and his former rival Mikhail Khodorkovsky.

Forbes magazine was not making a mistake when it called Putin the world's most powerful person in 2013. However, the Centre for Strategic Communications, a thinktank for the Kremlin's pet intellectuals, assessed his power more precisely last week when it acclaimed him "world conservatism's new leader". If you can rid yourself of the idea that being a conservative means merely supporting private enterprise, you will see what it meant.

Nineteenth-century radicals loathed Russia above all other states because it had a quasi-religious mission to preserve autocracy at home and promote reactionary regimes abroad. To true believers, the "Third Rome" of Christian tsarism defended the divinely ordained old order against the threats of liberalism, socialism, nationalism and modernity.

Putin is giving every sign that he wants Orthodox Russia to repel the satanic west again. He has appointed Dmitry Kiselyov to control the state's media network. Kiselyov earned Putin's admiration when he declared that gays "should be prohibited from donating blood, sperm. And their hearts, in case they die in a car accident, should be buried or burned as unfit for extending anyone's life."

In his state-of-the-nation address last week, Putin sounded like the most slavophile of patriarchs when he derided the liberal west as "genderless and infertile" and promised he would fight the western elite's "destruction of traditional values from the top".

If you think that makes him sound like a Christian Coalition or Muslim Brotherhood cleric, well that thought has struck others too. The leathery old American conservative "Pat" Buchanan, who has been involved in every foul movement on the American right since Richard Nixon's day, knows a potential collaborator when he sees one. Putin could be the leader of "conservatives and traditionalists in every country", he said, and lead the fight against the "militant secularism of a multicultural and transnational elite".

Brian Whitmore of Radio Free Europe quotes Moscow journalists talking of Putin's Russia replacing the old Communist International with a new "conservative international" that unites the religious and the repressive in a common front. You can see its work already. When Ukraine seemed close to reaching agreement with the EU, an advertising campaign, apparently financed by an oligarch close to Putin, warned that joining Europe meant allowing gay marriage. Fear of queers was used to keep Ukrainians in line.

Homophobia, the authoritarianism of the religious right – are these not the very vices that Obama and his "progressive" supporters have dedicated their lives to fighting? At home maybe. But abroad? Obama's conservative critics say he is the most "leftwing president ever". To my mind, no honourable definition of the left or of liberalism can exclude an awareness of the suffering of others – "internationalism" as we used to call it.

By this measure, not always popular in leftish circles, Obama's foreign policy is the most right wing since Nixon's, and not just because of his fondness for bugging half the planet. His indifference to human rights beyond America's borders matches Tricky Dicky's. The New York Times painted a depressingly believable picture of his boredom at having to deal with Syria, the greatest humanitarian crisis to date in the 21st century. "He often appeared impatient or disengaged while listening to the debate, sometimes scrolling through messages on his BlackBerry or slouching and chewing gum." He no more cares about Syria that he cares about the demonstrators in Kiev, Moscow or Tehran.

You may say "so what?" Public opinion in America and the west is against intervening in Syria or anywhere else. When Obama in Washington or, to a lesser extent, Ed Miliband in London spent three years arguing against every option – arming moderate rebels, enforcing a no-fly zone, carving out humanitarian corridors – they were doing what their electorates wanted. "Shrug your shoulders and turn your backs," the people said. "Get involved and you may help militant Islamists or drag us into a wider war."

The relevant historical parallel may explain their mistake. In the Spanish Civil War, Britain and France's refusal to help the legitimate government in Madrid repel the attack by General Franco produced the result they most feared. It was not just that Hitler and Mussolini had no qualms about "illiberal intervention" in Spain, any more than Russia, Iran and Saudi Arabia have qualms about illiberal intervention in Syria today. The fascist forces were strengthened for the wider conflict of the Second World War, but so too were the communists. Britain would not intervene in Spain in the 1930s because it did not want to help Stalin. Its very inaction helped him. The fact communists were willing to go to Spain and fight bolstered the prestige of communism. At least they preferred fighting to running away, people said.

History is repeating itself, or at least rhyming. As Saudi analyst Fahad Nazer says, for Sunnis around the world "exactly who ousts Assad is immaterial. If it is the Islamists, or even the terrorists of al-Qaida, then so be it."

I do not know what would have happened if western powers had imposed no-fly zones and safe havens three years ago. But I know al-Qaida is back from the dead and militant Islamists from Britain and across Europe have gone to Syria, as the International Brigades went to Spain, and we will have to have them back one day. I know that the war is spreading and that Europe will not be able to keep out its refugees for long. I also know that a supposedly "progressive" American president who bows his head to a Russia that announces itself as the head of a global reactionary movement is no progressive at all. And that those who shrug and turn their backs also have blood on their hands.