Deputy Secretary of State Christopher Landau greets Afrikaner refugees from South Africa, Monday, May 12, 2025, at Dulles International Airport in Dulles, Va. (Julia Demaree Nikhinson/AP)In the fall of 2024, the Department of Homeland Security had employees in dozens of countries, from Peru to Turkey, to vet the most vulnerable and persecuted individuals in the world for potential entry into the United States.Just one year later, those screeners…