YOU KEEP USING THIS PHRASE "NATIONAL SECURITY." I DO NOT THINK IT MEANS WHAT YOU THINK IT MEANS. Jonah Goldberg stays true to the Twelfth Commandment of the Republican Party ("Thou shalt smear Democrats as undermining the national interest"):
The 11th Commandment for liberals seems to be, "Thou shalt not intervene out of self-interest." Intervening in civil wars for humanitarian reasons is OK, but meddling for national security reasons is not. This would explain why liberals supported interventions in civil wars in Yugoslavia and Somalia but think being in one in Iraq is the height of folly. If only someone had thought of labeling the Korean conflict a humanitarian intervention back then, we might not face the horror and the danger from North Korea today.
You may remember similar arguments being used against -- among countless others -- Wesley Clark. The most obvious idiocy here is the contention that sacrificing many lives and immense resources to replace an (admittedly awful) secular dictatorship that posed no threat to the United States and had no substantial relationship with anti-American terrorism with an Islamist quasi-state was somehow in the American national interest (an implausible enough claim in 2003, and bordering on the insane at this late date.) And it's particularly rich given that, when their scaremongering about the dire threat posed by Iraq turned out to be wholly unfounded, the war's apologists began pretending that it was really a humanitarian campaign all along.
Admittedly, Goldberg is certainly right that the sectarian near-anarchy predictably created by the policy he advocated so vociferously is contrary to the American national interest. But in terms of defending an open-ended commitment to Iraq, this is neither here nor there unless there's some reason to believe that an ongoing presence in Iraq with a minor increase in troop levels can actually produce a strong, stable state. Goldberg doesn't actually have an argument about why we should believe this, which is not surprising since there is in fact no reason to believe that this is viable. It's true that the situation in Iraq is bad for the Iraqi people and bad for the interests of the United States, but this was a reason not to start the war, not a reason to continue it indefinitely when it shows no signs of producing a good outcome.