Some lawmakers have called Trump's strikes on Iran "unconstitutional" - so did he have the authority to order them?

'This is not Constitutional,' wrote Rep. Thomas Massie (R-Ky.), who last week made preparations to introduce a resolution under the War Powers Act.

Many politicians raised constitutional concerns about Trump’s acting without approval by Congress. But some GOP leaders offered support for his move.

Congress debates Trump's authority to strike Iran, with Republicans supporting and Democrats criticizing his actions, raising constitutional concerns.

Democrats and a few Republicans said the strikes were unconstitutional, demanding more information in a classified setting.

Democrats stress that only US Congress – not the president – has the authority to take the country to war.

Republican lawmakers cheered the strikes against Iran despite the president's campaign promises to keep the U.S. out of military entanglements abroad.

Members of Senate and House argue that US intelligence has not shown an imminent threat from Iran that justifies Trump’s unilateral action.

President Trump avoided asking Congress for permission before striking Iran, despite the Constitution saying only the legislature can declare war.

Trump’s unlawful strikes on Iran have laid bare the absence of any effective legal constraints on a U.S. president to use deadly force in the world.

Some lawmakers have called Trump's strikes on Iran "unconstitutional" - so did he have the authority to order them?

Trump approved the strikes without congressional authorization, leading to criticism from both sides of the aisle.