Well, here's the funny bit: Twitter doesn't need to decide. If someone in a major power, such as a G20 member country, is in a government position, they are a world leader. And because things are always contested, that same category can be extended to high-ranking members of opposition.

I'm going to take you at your word and accept that world leaders rarely tell the truth: so they should ALL get the same treatment then. But instead of stamping their output with just "fact-check this", why not unilaterally label all of it with: "may contain lies, omissions and half-truths"?