ISTANBUL

Several US legal scholars and lawmakers on both sides of the aisle in Congress said the Trump administration’s military campaign against Iran raises serious legal concerns under the Constitution and international law.

The strikes, launched Feb. 28, were carried out without congressional authorization. The US Senate is scheduled to vote Wednesday on a measure that could halt the offensive.

The conflict has since widened across the Middle East, with hundreds reported killed, including six US military personnel, as hostilities extend to Lebanon, Syria, Iraq, Israel and the Persian Gulf.

Critics said the Trump administration has provided differing explanations for the operation, at times describing it as a preemptive effort to weaken Iran’s military and nuclear capabilities, while at other times saying the strikes were necessary to protect American interests after Israel initiated its own offensive.

Marco Rubio, the US secretary of state, presented a somewhat different justification, saying the White House felt forced to strike Iran because its close ally, Israel, was determined to take action.

“It was abundantly clear that if Iran came under attack by anyone – the United States or Israel, or anyone – they were going to respond, and respond against the United States,” Rubio told reporters on Capitol Hill.

Wells Dixon, a senior attorney at the Center for Constitutional Rights, said after reviewing Trump’s reasoning that it reflects military goals.

“Those are military policy objectives,” said Dixon. “They are not a legal basis to launch an armed attack against another country.”

Sen. Tim Kaine said he supported US efforts to defend Israel during previous Iranian attacks, “but that’s a very different matter than the US engaging in the affirmative initiation of war.”

US and Israeli attacks Saturday on Iran have killed several senior Iranian officials, including Supreme Leader Ayatollah Ali Khamenei.

Tehran has retaliated with strikes targeting Gulf countries and US military assets in the region.