Are Trump’s strikes against Iran legal? Experts weigh in

Thomas Warwick breaks down the strike on Iran, its impact on Middle East safety, Iran's nuclear capabilities, and the chances of regime change.

Legal experts are already skeptical of U.S. President Donald Trump’s constitutional authority to launch new military action against Iran without Congress’ approval, especially if it leads to a prolonged conflict.

Like with the U.S. bombing of Iranian nuclear facilities last summer and the January military capture of Venezuelan President Nicolás Maduro, the attacks bring the issue of executive authority and the extent of presidential powers to the forefront.

The White House hasn’t presented a legal justification to the public, and Secretary of State Marco Rubio didn’t give a full accounting of one to members of Congress, multiple sources told CNN.

Trump “violated the Constitution by invading Iran because the Constitution is crystal clear on who has the authority to declare war and commit American service members to battle and that is Congress alone,” said Christopher Anders, a lawyer with the American Civil Liberties Union who is an expert on national security matters.

“The president has tried to grab that power for himself without getting authorization from Congress before doing so,” Anders added.

The Constitution unambiguously states that only Congress can declare or authorize war.

“This is very obviously a war,” said Ilya Somin, a law professor at George Mason University and a scholar at the Cato Institute, a libertarian think tank. “You don’t have to take my word for that — Trump himself says it’s a war.”

In his message announcing the strikes early Saturday, the president said: “The Iranian regime seeks to kill. The lives of courageous American heroes may be lost and we may have casualties. That often happens in war, but we’re doing this not for now. We’re doing this for the future, and it is a noble mission.”

CNN has reached out to the Justice Department and White House counsel’s office for comment.

While only Congress can declare or authorize war, Trump and other presidents have continuously cited the Constitution’s Article II, which says the commander in chief has the power to direct US military forces in engagements necessary to advance American national interests abroad.

In addition, the Supreme Court has been generous in approving Trump’s expansive use of power, most notably in its 2024 immunity ruling. That view contributed to the analysis to move forward under Article II authority when the U.S. struck Iran last summer, a senior White House official said at the time.

Article II was used in part to legally justify the recent U.S. military operation to capture Maduro. The Justice Department issued a classified legal opinion (and later a redacted version) saying Trump was not limited by domestic law in carrying out law enforcement operations overseas.

What if the conflict goes on longer?

That Justice Department’s Office of Legal Counsel memo also argued that the scale, scope and duration for the Maduro operation did not rise to the level of war in the constitutional sense and therefore did not require prior authorization by Congress, sources said.

The question of scale, scope and duration will be raised with the new actions against Iran. Trump, in his video announcing the strikes, described the military campaign as “massive and ongoing.” The U.S. military is planning for several days of attacks, according to two sources.

“The Justice Department has come up with an increasingly dubious series of arguments in attempts to defend such strikes, but virtually all of those arguments have depended on assertions that the strikes were limited and unlikely to lead to a broader conflict,” said Steve Vladeck, CNN Supreme Court analyst and professor at Georgetown University Law Center.

“Even if that were a legal argument, rather than a policy one, it’s hard to take that remotely seriously here,” Vladeck said.

Article II powers were cited for President George H.W. Bush’s use of force against Panama to overthrow dictator Manuel Noriega, former president Barack Obama’s use of air strikes in Libya and Trump’s actions in his first term against Iran and Syria.

“While the United States is not the world’s policeman, as its power has grown, the breadth of its regional interests has expanded and threats to national interests posed by foreign disorder have increased,” the Trump Justice Department’s Office of Legal Counsel wrote in 2018 regarding air strikes in Syria.

In addition, Democratic and Republican administrations have repeatedly stretched the 2002 Authorization for Use of Military Force Against Iraq, which authorized the Iraq War. An earlier AUMF that authorized action against al Qaeda and associated groups has also been used beyond what was conceived in the post-9/11 era.

“I think you could argue about the wisdom of it,” Somin said of the new US attacks. “I certainly wouldn’t shed any tears if the Iranian regime were to be overthrown. It’s an awful regime. It’s an enemy of ours and so forth, but the war that has been started here is unconstitutional.”