Ethnic cleansing did happen, but it wasn't just in one direction. Apartheid is race based discrimination, Israel mostly just has citizenship based discrimination these days(like most countries). War is also not the same thing as genocide.

> Supporting its "right to exist" is to support all of those things.

Do you think the US has a "right to exist"? You can make an equally if not more plausible claim that the US could only exist via ethnic cleansing, apartheid and genocide due to what happened to the Native Americans.