when a country like the U.S. chooses to initiate a war of aggression against a foreign population it is effectively just an assertion that there is no such thing as law when it comes to wielding geo-political power. in the case of the congressional vote to authorize force, that wasn't really an exercise of law. that was a public performance of assent to break the law. it was congress saying "we capitulate to your plans and will not attempt to interfere with the war".