Instead of a hypothetical you can just use the example from the article:

> Twitter said it would not ban President Trump despite incendiary tweets, including allegations that he threatened to declare war on North Korea.

Right, but using the example of Britain and Germany back in WW2 removes it from current politics and allows us to think of an example of a clear and direct incitation of violence that almost everyone thinks was legal and morally just and would have been appropriate to Tweet.

Threatening to declare war is a diplomatic tactic. Just because Donald Trump did it doesn't change tactics used by world leaders.

I don't recall any nukes dropping, or armies being deployed--but if you listened to the media around that time, it was 10 seconds to midnight. What we actually did see is people holding hands and crossing borders. Yet still, even today, we hear about the threat of war.