JD Vance was supposed to be spending the week promoting his new book, the kind of event a potential presidential candidate like the vice president typically uses to speak to a wide audience about his life and values ahead of a campaign.

Instead, the rollout of Vance's second book, "Communion: Finding My Way Back to Faith," has been largely crowded out by something else he's put his name on: the tentative deal to end the Iran war.

The Republican vice president has embraced the role of chief defender of the agreement he and President Donald Trump signed with Tehran, giving a series of interviews touting the memorandum of understanding as a success and releasing a video championing it.