The Senate rejected a resolution Tuesday seeking to end U.S. involvement in Yemen’s spiraling civil war, which has killed thousands of civilians and thrown the country into the “world’s worst humanitarian crisis,” according to the United Nations. But there’s a reason the senators pressed forward with the vote. Bin Salman may be touted as Saudi Arabia’s young modernizing reformer, but he is also widely considered the architect of the Saudi-led air campaign in Yemen, which has had disastrous results for the country and its civilians.