President Donald Trump's push to convert his planned triumphal arch near Arlington National Cemetery into a military complex has complicated a required federal review process and raised new legal and safety concerns.

Trump unveiled his new national security rationale Sunday in a post to Truth Social, saying that the 250-foot arch project - which he has framed for nearly a year as a tourist attraction - will now house drones, snipers and ammunition. The president said he was making the change at the request of the U.S. military.

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Critics of the plan saw echoes of Trump's ...