The post is referring to leftists who supported Assad because he was backed by Russia and Russia is hostile to the West.

Enemy (Russia/Assad) of our (tankies) enemy (the west)

Edit: I should say that I’m taking specifically about what the post has to say in regards to Ukraine. IDK that there are many tankies out here supporting Israel.

The United States and her western allies

The post is talking about tankies that think because US bad -> Russia is the enemy of the US -> Russia good. Which is obviously asinine