As the Trump Administration prepares for the U.S. to co-host the World Cup this summer, easing travel rules for sporting events amid otherwise tightening immigration policy, some members of the global soccer community are saying: “Stay away from the U.S.A.!” That particular phrasing came from Mark Pieth, a Swiss attorney who chaired the Independent Governance Committee’s oversight of FIFA reform between 2011 and 2013, in an interview with Swiss newspaper Der Bund last week. But calls for a boycott of the world’s biggest international soccer competition have gained traction among other prominent soccer figures, lawmakers, and fans. The U.S. is...