It's a pity they didn't discuss Bosnia and Kosovo, two places where US-led intervention definitely did a lot of good.

Libya was Obama's Kosovo, a conflict where the US and allies quickly intervened to stop an autocrat's murderous rampage. The civil war Libya has experienced over the last decade does not mean overthrowing Qaddafi was a mistake - if anything, it might have made sense to put US troops in Libya to help build up the forces of the UN-recognized government, rather than keeping troops in Afghanistan for far too long.

Had Obama intervened in Syria in 2013, it could have been his Bosnia, a conflict where a US president intervened to weaken (not overthrow) a thuggish regime after initially dragging his feet. Launching air and missile strikes alongside France, and arming the Free Syrian Army to the teeth, would have helped the forces of decency stand strong as an alternative to both Assad and jihadists. Instead, Obama made the big mistake of taking a deal offered by Putin that left chemical weapons in Syria. US non-intervention left a void for Russia and ISIS to fill, contributing to a massive refugee crisis.

Diplomacy in Syria in 2011 may have been worth a try, but in any case it was foolish for Obama to call for Assad to step down if he didn't intend to do anything to bring that about. The arc of history (if such a thing exists) does not bend on its own. It requires human action to bend it. The Iraq war hawks were not the only people to be mistakenly optimistic - Obama had too much faith in history turning out alright in the end.

I respect Obama, and I agree with most of his foreign policy decisions. Drone strikes; Iron Dome; killing Bin Laden; pushing Mubarak out; intervening to save the Yazidis; Iran sanctions and the nuclear deal; the response to Ebola in West Africa; diplomacy with Cuba; trade deals with Colombia, Panama, and South Korea; negotiating TPP (which Congress should have passed); the European Reassurance Initiative; Power Africa - all these made sense, and many achieved good results. But I really hope he comes to regret his non-intervention in Syria, just as Clinton came to regret his non-intervention in Rwanda.