This is very sad. Unfortunately, this will keep happening until ISIS is stopped.
Or, when obama is no longer president.
This seems more like a protracted hostage situation, with 'no more air strikes' being the demand that if not fulfilled, leads to another dead hostage. This framing of the situation does target the president directly, but not because he is Obama: the president is the only person who can 'stop' the next murder.
There really is only one way any president should respond to this. In public anyway.
I doubt there are very many people in the middle east that believe that the US currently isn't meddling and playing games in each of these conflicts. If you were to speak to people from the area, the huge amount of paranoia would probably shock you. Even worse than the Russians. And they believe, rightly or wrongly, that Obama is just weaker and more devious, while believing that ISIS is controlled by the US through countries like SA and Qatar.
I do not agree with your assessment of Obama's skill as a statesman though, and I do not believe that the world in general sees him as weak or feckless, as some pundits would have us believe. I think that to the extent that America's position has weakened in his time respective to international relations, it has done so due to two factors - congressional dysfunction (which isn't exactly new, but has for sure worsened) and the Wikileaks/Snowden revelations. Those revelations cost us the moral high ground, and my opinion is that Obama's vocal desire for coalition building as well as his cooperation with local forces around the globe has gone a long way to restore our position as responsible world leaders, albeit in a different light.