The fact that the biggest national security news out of the debate tonight was Bernie Sanders emphasizing that he is not, in fact, against all military action, under all circumstances, at all times, tells you about all you need to know about the national security policy of the Democratic Party. These candidates are much more comfortable in discussing their dismay over the 2008 financial crisis, or the 2003 invasion of Iraq, or, in Sander's case, their opposition to the war in Vietnam than they are in speaking frankly about the foreign policy legacy of the Obama administration.
That's not to say that there are no differences among the field—and indeed, not a single candidate straightforwardly supported the current policies of the current president. Democratic primary voters have a choice among the leaders in the Democratic polls: slightly to the right of Barack Obama, with Hillary Clinton; or ever so slightly to Obama's left, with Sanders and Martin O'Malley. (Jim Webb constitutes an interesting wild card, and Lincoln Chaffee... well, who cares?)
Clinton's substantive statements largely took the form of a defense of her record as Obama's first term secretary of state. She feels that both the goals and the multilateral tactics of the Libya intervention were in large part justified, and implied that she would take a tougher line with Putin and Assad in Syria today, suggesting that "safe-zones" need to be established. She avoided hitting Obama directly over his handling of the Middle East crisis by suggesting that it was much easier to handle Medvedev, when she was in the administration, than it has been to handle the return of Putin in the president's second term. When Jim Webb gave a complicated answer (for a televised debate) suggesting that the NSA needs to collect vast amounts of data to do its job, but must be required to delete it eventually, she nodded her head in approval. Her foreign policy, she implied, would be something like that of Obama's first term, or perhaps like that of her husband's two terms.
Then there is Bernie. For the senator from Vermont, Edward Snowden might deserve some sort of punishment, but his effort to "educate" the American people about what their government was doing deserves to be taken into account during any judicial proceeding. Syria is a "quagmire in a quagmire" and we have no business there. His support for the initial strike on Afghanistan in 2001 got some mileage, serving as the (sole available?) proof that Sanders is not a pacifist, as he was at pains to point out. O'Malley sought to occupy a similar space in the debate by explicitly opposing a no-fly zone in Syria, and endorsing what he archly called Obama's "long game."
Webb marked out his strong opposition to both the Iran deal and the invasion of Iraq, thus staking out a position that is not particularly welcome in either party. He also was dedicated to some sort of rhetorical pivot to the Pacific, awkwardly trying to shift the conversation to the threat from China when it did not appear particularly relevant. There was much in his answers to argue with, but he is a serious man who doesn't fit any extant boxes in today's parties. He doesn't stand a chance.
As for the Democratic candidates polling well, Sanders and Clinton, voters face a choice between a foreign policy of even more dramatic withdrawal from the world than President Obama's, or the milquetoast Democratic orthodoxy of Obama's first term and of the last Clinton era. It will be interesting, if Biden enters, to see if he also feels the need to create some daylight between himself and his boss.