the u.s. kurdish allies inside syria. this becomes the critical question, the critical red line, perhaps, for jim mattis, because by the president's decision to withdraw u.s. troops from syria, leaves those kurdish fighters that the u.s. had pledged to support, it leaves them abandoned. it leaves them at risk. mattis is a military man of 40 years. you do not leave your friends on the battlefield, and that's the position president trump put him in. so, he met with president trump later in the day about 3:00 we're told at the white house, tried to convince the president one last time to change his mind about syria. the president did not, and it is at that point that mattis had no option in his mind but to resign. this is not a surprise if you know jim mattis. it perhaps surprising that it didn't happen before this, but he also tonight knows that the