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Here’s what you need to know:

Iran gets an all-caps warning

• President Trump threatened President Hassan Rouhani on Twitter late Sunday with “CONSEQUENCES THE LIKES OF WHICH FEW THROUGHOUT HISTORY HAVE EVER SUFFERED,” after the Iranian leader said any conflict with his country would be the “mother of all wars.”

Mr. Rouhani had earlier threatened to disrupt regional oil shipments if U.S. sanctions blocked Iran’s exports, a position the supreme leader, Ayatollah Ali Khamenei, said he supported.

• Mr. Trump’s warning came hours after Secretary of State Mike Pompeo gave a speech accusing Iran’s leadership of widespread corruption.