The UN Security Council, as outlined in Article 39 of the UN Charter, has the ability to rule on the legality of the war, but has yet not been asked by any UN member nation to do so. The United States and the United Kingdom have veto power in the Security Council, so action by the Security Council is highly improbable even if the issue were to be raised.

No one cares and even if they did it can be vetoed.

Countries shouldn’t be able to veto things about themselves. That’s stupid.