Commentary Until the Trump administration began its experiment in 21st-century American transactional diplomacy, “intractable international problems” dismayed, vexed, and bamboozled establishment diplomats, whether they hailed from Washington’s Beltway morass, U.N. agencies, or cachet townhouses in European capitals. I specify American transactional diplomacy—meaning negotiating and then concluding two-way deals (bilateral agreements, in diplo-speak) that demonstrably benefit two antagonistic nations. The payoff of conflict and creating peace level: The deal diminishes their level of mutual antagonism, promotes kinder words, and opens opportunities for wealth-creating interaction. Aside to open-minded readers: “American” indicates the two-way deal was brokered by the United States as a third party. American means U.S. power and prestige explicitly support the agreement. It means American DIME power—American Diplomatic, Intelligence/Information, Military and Economic power—adds steel to the deal. Note I translate common-sense terms into diplo-speak so elite media types will understand it. Another point in the same vein: Trump administration diplomats …