(BEIRUT) — An Islamic State suicide bomber targeted a joint convoy of U.S. and allied Kurdish forces in northern Syria on Monday, marking the second attack against U.S. troops in less than a week and further highlighting the dangers surrounding U.S. plans to withdraw forces after a declaration that the extremist group had been defeated. The attack happened on a checkpoint on the edge of the town of Shaddadeh in the Hassakeh province, on a road used by local Kurdish fighters and the U.S.-led coalition fighting IS militants near the Iraqi border. U.S.