JD Vance, the vice president, sat down with Nigel Farage, a longtime supporter of President Trump whose party, Reform U.K., is leading in British polls.Vice President JD Vance began his family vacation in England last Friday with a lightning round of carp fishing. He hasn’t slowed down since, taking part in conference calls about Ukraine, huddling with Britain’s foreign minister, David Lammy, and meeting fellow right-wing political figures.On Wednesday morning, it was the turn of Nigel Farage, the leader of the insurgent, anti-immigrant party Reform U.K. He sat down with Mr. Vance, according to an official familiar with the vice...