I’m not an electrician, but I recall that this video explains it pretty well (along with other interesting things): https://www.youtube.com/watch?v=K_q-xnYRugQ

I don’t think that’s who they were calling Russia.

I, for one, haven’t seen people over-using the word “tankie”, I haven’t seen people getting called tankies for the reason alone that they are leftists or even communists.

However, I’ve seen many tankies insisting that the word is meaningless or that it just means anybody on the left.

People I’ve seen using the word tankie have been surprisingly consistent about who they call a tankie: supporters of authoritarianism, especially Putin and the CCP.