I don't think Obama is a particularly good or bad man, I think he's just a good politician who went in there and did "what he was supposed to do." Stupid and evil wars existed before and after him. He didn't do anything to fix it, but he didn't start it either. The President doesn't have as much power as we may believe.
With these "wars" in particular he actually does have a great deal of power. They aren't actually wars but "military actions" for the most part. The commander in chief can unilaterally order the armed forced to withdraw if he so wished. Instead Obama ordered drone strike after drone strike, bombing after bombing (so many in fact that there was serious concerns that we would run out of bombs[0]). His merits as a president can be debated, his merits as a peace prize winner cannot. He simply did very little to promote peace and much to prevent it (see Syria).
[0]http://www.cnn.com/2015/12/04/politics/air-force-20000-bombs...