A conflict which has been going on since 632 is not going to be 'solved' by any US President, although President Obama's denial of ISIS' capabilities as the being the "JV", ignoring the 'red line' he supposedly drew and then ignored regarding Assad certainly hasn't helped the situation.  His most positive action was helping get rid of the large amounts of chemical warfare stocks in Syria.  Of course, Putin was the one who got that done; maybe he had already decided to send Russian troops and planes to Syria and was just planning ahead?  That concept seems to be lost on US intelligence and military forces going back for a couple of decades.