I wouldn’t say this is due to simply being far-left. It may have started as such, but then they decided to subdue their political beliefs to geopolitics, and pursue geopolitical beliefs first and foremost. And those geopolitical beliefs favor a competition-minded worldview, a “might makes right” one, and a black’n’white perception. Tankies have just started being fanatic for one of the sides, almost being nationalists for another country, just like far-rightists.