It was May 2017. The Saudis were growing increasingly nervous. For more than two years they had been relying heavily on U.S. military support and bombs to defeat Houthi rebels in Yemen. Now, the Senate was considering a bipartisan resolution to cut off military aid and halt a big sale of American-made bombs to Saudi Arabia. Fortunately for them, despite mounting evidence that the U.S.-backed, supplied, and fueled air campaign in Yemen was targeting civilians, the Saudi government turned out to have just the weapon needed to keep those bombs and other kinds of aid coming their way: an army of lobbyists.