It hasn't been practiced. If it starts being practiced, however, it may be as harmful as Ilya claims, so his argument deserves a response. But saying:

I'm saying we live in a world where a right to self-determination has been recognized for something like a century now, even if it does not come with an automatic invasion authorization from the UN Security Council. So far, I'm not sure if it's been all that bad

Is not evidence because it hasn't been really practiced so far.

Also:

do international abstractions have no force and no consequences

I'm not claiming anything about other abstractions, some of which definitely have force, just this one.