As the war in Ukraine grinds into another season of loss, a quiet but consequential debate has opened within the American government about the nature of persuasion itself. President Trump, diverging from a Congress that has chosen the language of punishment, is instead offering Russia economic enticements — a wager that what draws an adversary forward may prove more powerful than what pushes them from behind. The outcome of this philosophical split between carrots and sticks may do as much to shape the war's end as any battlefield development.