Jim Antle makes the understatement of the week:

And by seeming open to preventive war in Iran, Huntsman may not be the ideal candidate for foreign policy restraint.

Worse than that, it undermines the main argument for why Huntsman should be taken seriously as a candidate: his reputation for greater foreign policy experience and understanding. In a mostly hawkish field that ranges from the ridiculously alarmist (Santorum) to the irresponsibly alarmist (Romney), Huntsman is supposed to possess the sobriety and sanity that other “mainstream” candidates lack. His “I can’t live with a nuclear-armed Iran” line may be nothing more than lip service, but the fact that he is willing to indulge one of the most dangerous ideas in current foreign policy debate badly weakens the one thing that distinguishes him from the other candidates.

As Heather Hurlburt points out, Huntsman’s position on Iran is simply an ill-informed one:

The Iran attack call is interesting because, contrary to what you might think, the U.S. military and many nonpartisan and bipartisan national security figures think such an attack would be a disaster for our security, for our economy and for our ally Israel.

Huntsman’s willingness to consider starting a war with Iran is all the more striking when he brings it up in the middle of an otherwise reasonable speech.