American airstrikes targeted a group of Syrian militia vehicles after they ignored U.S. warnings and violated a “de-confliction zone” on Thursday. CNN reports that the strike occurred near a base American forces use to train allied Syrian opposition fighters. A convoy of twenty vehicles approached the town of An Tanf on Wednesday night, evidently searching for opposition fighters and raising concerns among the U.S. coalition. A total of thirteen vehicles penetrated the de-confliction zone, but the U.S. did not take action until five of them came with 29 kilometers of the base. When five Syrian military vehicles persisted in approaching the base, the U.S. conducted a “show of force” with two warplanes to persuade them to halt. When the Syrians insisted on proceeding into the area, the U.S. planes…