At least that was honest. No pretense about handing them over to a bogus "impartial" court.
Moreover it's not clear that Milosevitch was the enemy. And the UN never authorized the war. And clinton never declared war.
At least the Romans were finicky about such matters. They sided with allies, fought against enemies, and always took care to go through the proper rituals for declaring war.
We nevered declared war on North Vietnam, and the UN didn't authorize it.