It doesn't matter whether Russia is anti-imperialist or not, but whether it performs an anti-imperialist function and ultimately serves the cause of anti-imperialism. People like to debate whether this or that org or country is anti-imperialist, treating anti-imperialism as a metaphysical property that's imbued within something and not as a real material movement towards the end of imperialism.

I don't know whether Iran is truly anti-imperialist in the sense that I don't know whether Khamenei has secret designs in creating a Shia caliphate that covers all of Western Asia or a neo-Achaemenid Empire. But what I do know, based on what has happened and is happening in the material world, is that Iran is playing a pivotal role in undermining Western hegemony by being a key player in the Axis of Al-Quds. I don't know whether Iran has malicious designs in turning Palestine into an Iranian neocolony, but what I do know is that Iran has done more to help the Palestinian resistance against the Zionist entity than any other country. One is mere speculation while the other is cold reality.

The sad truth is that anti-imperialist forces, principled or otherwise, within the imperial core is weak and enfeebled enough that the cause of anti-imperialism is advanced through incompetent Western imperialists rather than Western anti-imperialists. Trump's incompetent buffoonery has done more to undermine Western imperialism than any other anti-imperialist force within the West.

Perhaps this is one reason why Western leftists love to treat anti-imperialist as a metaphysical property. They retreat to idealism because even aspiring non-Western imperialists who no longer want to play second fiddle to Western imperialism are doing more.