capitalism in the west is fair and free but in Russia is ruthless and authoritarian.

Correct. The natural progression of late stage capitalism is a move further towards authoritarian capitalist kleptocracy.

How do we tell if a nation is antithetical towards western imperialism, or if we're just witnessing the beast eating its own tail?

I would argue that we should look at the material motivations, and how capital is distributed within the nation. But I guess the enemy of my enemy is more catchy....