The officially recognized definition of a Tankie is one who is a strong supporter of communism. Which, I think we all agree is considered a “left” wing ideal.

It’s also strongly authoritarian, but it’s solidly in the authoritarian left. So people calling others “Tankies” are, in theory, more right-wing than the people they’re insulting. It’s a left-punching insult.

Usually these people are strong supporters of China and the old Soviet Union and are staunch critics of ‘imperialist’ nations such as Britain and the USA.