The President has inherent constitutional power to declare foreign diplomatic personnel persona non grata and to expel them forcibly from the United States; the exercise of this power is consistent with international law, including specifically the Vienna Convention on Diplomatic Relations.
Inherent in the President’s power to recognize foreign countries and their ministers is implied power over the physical premises of diplomatic properties, including power to take actions necessary to protect embassies from damage, and to deny possession to or to eject those not recognized as diplomatic personnel of the sending state.
A foreign diplomat who has been declared persona non grata and ordered to leave the country does not lose his diplomatic status, and thus should not be able to assert any legal entitlement to remain in the United States under the Immigration and Nationality Act; nor should such an individual be able to frustrate or delay execution of an expulsion order by renouncing his diplomatic status. The Secretary of State may revoke the visas of diplomats declared persona non grata to forestall their invocation of the INA as a basis for challenging the Pre sident’s expulsion order.
Federal law enforcement officials, particularly the Secret Service, have authority to protect Iranian diplomatic property against third parties, including any persons not currently recognized by the United States as accredited diplomatic personnel. The President is authorized to call on the full range of his resources in the Executive Branch, including the military, and also on the resources of state or local law enforcement agencies, to carry out an expulsion order in this situation.
The Due Process Clause of the Fifth Amendment at most requires only a determination that a diplomat about to be expelled from the United States pursuant to the President’s order is in fact the person ordered to be expelled; an expulsion order is arguably subject to judicial review, on a writ of habeas corpus, but only on the limited grounds of mistaken identity.