Some lawmakers in both parties question the legality of Trump's Iran strikes

 https://www.nbcnews.com/politics/congress/lawmakers-both-parties-question-legality-trumps-iran-strikes-rcna214316

The legal question flows from the War Powers Resolution, a law that says a president can launch military attacks only in three circumstances: a “declaration of war,” a “specific statutory authorization” from Congress or “a national emergency created by an attack upon the United States, its territories or possessions, its armed forces.” Congress has gradually ceded those powers under presidents of both parties in recent years.