Thus spoke President Obama in a speech where he made the right choice of a way forward for conflicts in areas where suggesting keeping troops on the ground should lead to a head examination, according to the defense secretary. Raids like that on Osama bin Laden and drones are probably a preferred way of future operation.
After the financial crisis when the tide turned on America, I actually wrote a post summarizing the situation in the way Obama did but he had problems with the Republican party and the military and went into the surge attempt. After some effect of the surge, Obama can now say that more military and a prolonged military engagement is doomed to fail and have his people's majority on his side.
Another fact that might be affecting the American opinion is that China is just moving ahead with their economy not paying any attention to problems in the world. The futility of the Arab Spring in terms of what can actually be achieved with military means might also play a role. The successful raid against bin Laden renders an opportunity for a mission accomplished of some sort.
Carl Bildt reacted strongly on the idea that Americans should focus on their own problems but is he really surprised? This notion has matured over the last three years. Also, if you want to do nation building it might pay off to select countries that are in a significantly better shape than Afghanistan and Somalia to build credit and to gain experience. Starting out with one of the bottom tier countries might just give development strategies a futile and failing air. Obama is giving people like Westerwelle and Bildt problems though because their cause for being in Afghanistan for their populaces, nation building, is significantly weakened.
As I claimed ahead of the Libya debacle, it is one thing to wish you can prevent ethnic cleansing but another to actually being able to do something. We might stand ahead of an era where the failing states will have to be left to their fate while the establishment focuses on countries that can be saved by others.