Experts in military law are flagging that there is a huge legal problem that President Donald Trump faces as he heads into another Middle East war. Reporting Friday, ABC News noted that the White House is running into a problem after it blew up an unarmed Iranian ship that was in international waters off the coast of Sri Lanka, doing naval exercises with India. If the U.S. were at war, the bombing would have been legal, but without declaring war officially, there is a legal question about the move.Speaking to the press this week, Speaker Mike Johnson (R-La.) reiterated that the U.S. is "not" at war and the attack in Iran is a "limited operation."That's not what Undersecretary of Defense for Policy Elbridge Colby said, however. “I think we’re in a military action at this point. I will leave to Congress and lawyers from the administration, et cetera, to determine," he said. "The U.S. will come to bitterly regret precedent it has set," said Iranian Foreign Minister Abbas Araghchi. Thus far, the "not war" involves more than 12 countries. Both branches of Congress voted on Thursday on a War Powers declaration that would have put restrictions on Trump to wage a new war. Both failed. However, there still hasn't been congressional approval for Trump to bomb Iran. Under U.S. law, Trump has only 60-90 days to accomplish his goals and withdraw, unless Congress gives him approval. Jim Lobe, Washington Bureau Chief of the international news agency Inter Press Service, writing for "Responsible Statecraft," warned that it may ultimately be considered a war crime. It underscores why military experts say that Congress needs to declare war quickly. Retired Lt. Col. Rachel VanLandingham, a former judge advocate general in the U.S. Air Force, told ABC News as much, noting it's necessary “because this is a war [in which they're] going to go after the Iranian Navy," even when naval assets are outside the Middle East.“The Iranian Navy is not small, right? It could be in places like outside of Sri Lanka and international water," he added. If the U.S. declared war, the ship would have been a lawful target, one ex-government lawyer said. Attacking a ship in international waters without declaring war is "political" and not legal, VanLandingham explained. "When you're going to have such global implications, that's one of the reasons the founding fathers said Congress gets to decide wars of choice," she said. "The fundamental legal problems under both U.S. and international law" of the submarine engagement, "relate to the underlying use of force in this war against Iran," said Brian Finucane, who previously served as the attorney-adviser at the State Department from 2011 to 2021.