The call to the U.S. ambassador to Tajikistan came in Monday. On the line, two U.S. officials said, was Rep. Markwayne Mullin (R-Okla.) with an unusual and urgent request: He needed assistance in transporting a huge amount of cash into the country, saying he was going to neighboring Afghanistan to rescue five American citizens, a woman and her four children, stuck in the country. They planned to hire a helicopter for the effort.