Why do some cheer on Russian bombing in Syria, dismissing out of hand the evidence from Physicians for Human Rights, Amnesty International, and Human Rights Watch  that they are criminally targeting hospitals? Why do some try to justify Russia’s takeover of Crimea or its blatant intervention in Ukraine?
Apologetics for Moscow, of course, has a long and ignoble history on the left. There is no excuse for this betrayal of left values, but we can at least understand some of the reasons that people held these wrongheaded views.
In the past, many Americans who were committed to progressive causes - especially civil rights and labor rights – joined the Communist Party because it was an organization actively and powerfully engaged in these struggles. They were aware that CP membership required following the Soviet line on foreign policy questions, but many joined despite this, not because of it. Now in fact even their contribution to the civil rights and labor movements was compromised to some degree by their allegiance to a hierarchical party that was subservient to Moscow’s foreign policy. (How many honest radicals became alienated from the left because of the CP defense of the Moscow Trials or the Hitler-Stalin Pact? How much harm was done to the left by the CP supporting the trial and conviction of Trotskyists under the Smith Act in World War II?) Still, we can understand why many CPers believed that their participation was furthering the cause of social justice at home, and, hence, why they gave the Soviet Union a pass.
Another reason for leftists to be soft on the Soviet Union was that internationally it was generally on the side of the great anti-colonial struggles of the day. Its economic and military aid and its diplomatic support helped many Third World nations break from Western colonial or neocolonial rule. Now this was never as consistent or as selfless as Moscow’s acolytes suggested. Soviet opposition to the Eritrean liberation struggle, for example, was horrendous, and as early as 1921 the new Soviet state sold out communist militants in Turkey in order to maintain its relationship with Mustafa Kemal. Moreover, national liberation that was supported with Stasi agents setting up a security apparatus was hardly very liberating. Likewise, Soviet support to the Republic during the Spanish Civil War was such that even if Franco had been defeated, Spanish democracy was unlikely to survive. In addition, it should be noted that great powers often tried to weaken their rivals’ colonial empire without at all being progressive - think of the German Kaiser’s aid to Irish rebels. Nevertheless, there is no doubt that the Soviet Union played an important role in hastening the end of colonialism, and so we can understand why many leftists were enamored of it. Soviet prestige was also enhanced by its role in the defeat of Nazi Germany (though this followed its pact with Nazi Germany).
A third reason that some leftists wrongly but understandably championed the Soviet Union is that the country was committed, rhetorically at least, to socialism. Principled socialists differ in their assessment of when the Soviet Union became a repressive state - I would date it from the crushing of the Workers’ Opposition and Kronstadt - but there is no doubt that by the mid-1920s there was no democracy in the Soviet Union and, because there can be no socialism without democracy, nor was there socialism. Beyond their rhetorical socialism, members of the Soviet bloc proclaimed their allegiance to social justice, and to some extent this was not all just words. Because social justice, like socialism, has to include democratic rights, the Soviet Union and other members of its camp were crucially deficient in social justice. But they did tend to have greater social and economic egalitarianism and more developed social welfare policies than many Western states. These accomplishments had the unfortunate effect of erroneously suggesting that we face a trade-off: we can have either economic justice or democracy, but not both. It is true that a resident of Brazil’s favelas might choose Cuba’s heath care over her own country’s formal democracy. But Costa Rica, no paragon of socialist enlightenment, offers both democracy and a life expectancy equal to that of Cuba’s. Still, to many leftists the fact that the “communist” countries, led by the Soviet Union, declared themselves to be pursuing socialism made it easier to overlook their misdeeds.
The question is, why do many leftists today close their eyes to Russian crimes given that each one of these lame but understandable reasons for Soviet apologetics no longer applies?.
Where the Soviet Union generally backed parties around the world and in the United States that were on the left, at the moment Moscow seems to be much more supportive of far right parties than of left ones.  In the United States, Putin’s backing of Donald Trump over Hillary Clinton was clear, whether or not it is confirmed that Russia hacked emails with the intention of helping the Republican candidate. So left apologists for Putin are not turning a blind eye to the crimes of a regime that at least is promoting the U.S. civil rights movement. No, their blind eye is to the crimes of a regime that favors the candidate who will preside over one of the most rightwing governments in U.S. history.
Where the Soviet Union generally stood against colonialism, in this post-colonial age Putin’s Russia is now one of the leading powers seeking to acquire or hold on to territory by force: Chechnya, South Ossetia, Eastern Ukraine, Crimea (the latter annexation condemned by a vote of 100-11 in the General Assembly, with 58 abstentions).
Some leftists like to claim that Russia, Syria, Iran, and Hezbollah constitute an “axis of resistance” that has heroically been challenging U.S. and Israeli imperialism. This account ignores the fact that in the 1970s Hafez al-Assad intervened in Lebanon against Palestinians and the Lebanese left, and more recently Bashar al-Assad partnered with Washington in torturing prisoners.  Today, hundreds of Palestinians languish in Bashar’s torture chambers. . If this is an axis of resistance, we might consider adding the European far right parties that have been supporting Assad. Indeed, given that Moscow has been a substantial purchaser of Israeli military drones  and a leading supplier of its oil and has coordinated its bombing in Syria with Israel,  perhaps Israel too should be considered a member of the axis of resistance? After all, Israel did absent itself from the UN resolution condemning the annexation of Crimea. 
And where the Soviet Union could boast some progressive social policies, these are things of the past. Putin has explicitly adopted a rightwing ideology, drawing on émigré and even fascist philosophers.  Putin’s party, United Russia, with three-quarters of the seats in the Duma, has officially adopted “Russian Conservatism” as its position. As RT, the Russian-government sponsored news outlet, reported:
Having called themselves “conservatives,” the members of United Russia “have simply determined their place” as a right-wing party, political scientist Dmitry Travin said. That means that they are “politicians who defend values of the market economy based on national traditions,” Rosbalt news agency quoted him as saying.
At the same time, they “are not staunch defenders of freedom as liberals,” and they are not “followers of egalitarianism as social democrats,” he said. 
In terms of Islamophobia and anti-LGBT repression, Russia makes the United States look like Paradise. Male life expectancy in Russia is six years less than in Brazil and a decade less than in Mexico; its spending on education as a share of GDP is 80 percent that of Mexico and less than three quarters that of Brazil.  In terms of the size of the public sector, Russian government spending as a percent of GDP is smaller than that of Japan, Greece, the UK, and Spain (and its military spending is a far greater share of its overall government spending than any of these countries).  Neither in practice nor in inspiration nor even in rhetoric does current-day Russia reflect left values.
So why then the left enthusiasm for Russia?
For some, no doubt, it’s simply nostalgia. The U.S. Peace Council, a slavish Moscow tool during the Cold War, fondly recalls the Soviet alliance with the Baathist regime in Syria under Hafez al-Assad, and so perhaps it’s a simple move to glorify Russian support today for the successor to the Assad dynasty. (And thus the Peace Council’s awful propaganda trip to Damascus and subsequent participation in Syrian-government sponsored propaganda events. )
But wistful longing for the glory days of the Soviet Union doesn’t explain most left attachment to Russia. Instead it’s the pernicious doctrine of “the enemy of my enemy is my friend” that unfortunately has permeated large sectors of the left.
A civilian airliner is shot down over the Russian-backed break-away zone of Ukraine, the United States (among others) accuses the Russians of being responsible, and the automatic, reflexive response from some is that this was either a Western false flag operation (an intelligence concoction) or at a minimum a tragedy for which the United States and its allies bear primary responsibility. That Russian propaganda on the matter was so easily refuted merely confirmed for some how devilish the false flag operation really was. 
An aid convoy is bombed in Syria. Washington accuses Russia or Syria of being responsible. Given that Assad had a clear policy of forcing Aleppo to “surrender or starve,”  Washington’s accusation was certainly plausible, but further evidence left little doubt as to Russian/Syrian responsibility.  But to some on the left, the fact that the U.S. government said it made it false.
Now it is true that any time two imperial states contest for power each is going to try to push a one-sided, jingoistic narrative of the differences between them. Skepticism about the claims of one’s own government is certainly warranted. During the Soviet period, in the United States the official line tried to portray Moscow as wholly responsible for the onset of the Cold War, and as being in the wrong, the aggressor, in every single international dispute. It was and remains important to contest this dominant view. That doesn’t mean, though, that we should have dismissed the tendentious U.S. narrative only to adopt the equally tendentious Soviet counter-narrative — dismissing as Western propaganda such things as the gulag or the secret clauses in the Hitler-Stalin pact or the Katyn massacre or Soviet aggression in Hungary in 1956 or in Afghanistan in 1979-88. It was entirely possible — and right — to reject both the U.S. and the Soviet propaganda lines. The forerunner of the current Campaign for Peace and Democracy— the Campaign for Peace and Democracy East and West — famously got Western Central America activists to sign on to a statement condemning Soviet policy in Eastern Europe and got East European dissidents to sign on to a statement condemning U.S. policy in Nicaragua and El Salvador. It’s this sort of rejection of both sides and their lies that ought to be key to any left politics.
If Russian hacking interfered in the U.S. election, it is not enough to point out Washington’s sordid record of interfering in foreign elections. The left condemns U.S. interference in foreign elections and we ought to condemn Russian interference as well (and not just in the United States). While some of the attacks on Russian hacking by the Hillary Clinton camp (“Ronald Reagan would be rolling over in his grave” ) do indeed smack of McCarthyism, there’s nothing wrong with the left denouncing Russian crimes. And all the U.S. crimes in the world don’t justify Russian crimes. Nor should U.S. crimes lead us to withhold our criticisms of the crimes of Moscow, any more than Russian crimes would lead us to withhold our criticisms of the crimes of Washington in Iraq, Honduras, and elsewhere.