Right now you're watching the most expensive photo op in history.
He wanted to stumble his senile ass into the 911 remembrance, (where NOBODY WANTS HIM) and break his arm patting himself on the back for ending the war 3 previous POTUS couldn't. THAT was the reason for Aug 31 and none other, so his glorious withdrawal was still in the news cycle.
Listened to political advisors instead of Intel and Generals.