In a 1996 book, Le siècle des idéologies, French philosopher Jean-Pierre Faye articulated a “horseshoe theory” of politics, by which the extreme of Left and Right begin to curl back toward one another as they get more and more alienated from centrist politics. As one might expect, the theory has plenty of critics—since, needless to say, few leftists want to be lumped in with their opposite number on the Right, and vice versa. But any objective observer can see that there are a number of ideological elements—a tolerance for street violence; a desire to censor opposing viewpoints; a weakness for powerful strongmen; a disdain for due process and democratic politics; and a tendency to lionize foreign autocrats as offering some viable alternative to liberalism—that really do answer to horseshoe-theory analysis.

On the Left, opposition to the West’s support for Ukraine isn’t difficult to explain. Leftist figures such as Corbyn, Noam Chomsky, and Australian journalist John Pilger generally view the United States (and the West in general) as the main engine of evil in the world, and so are disposed to respond to any geopolitical crisis simply by putting down stakes on the opposite side of Western interests. (And to such extent as they can bring themselves to criticize the West’s enemies, they will usually add, in the same breath, that their misdeeds are scarcely worse than those of white imperialists). It’s a pattern of rhetoric that goes back generations.

When it comes to explaining right-wing agitation against Ukraine (or against Western support for Ukraine, at any rate), on the other hand, things are more complex. From the McCarthyism of the 1940s and 50s, to Ronald Reagan’s famed “Tear down this wall” speech of 1987, conservative US politicians traditionally have been hyper-vigilant in regard to Russian militarism, sometimes to the point of paranoia.

But that reflex has been ebbing since the Cold War. The binary dynamic of capitalism versus communism is a thing of the past. China, not Russia, is now seen as America’s most important competitor on the world stage. And since 9/11, militant Islam has rivalled (and often surpassed) communism as an object of concern within the Republican Party and conservative politics more generally.