In his March 21st letter to Congressional leaders, President Obama justified the Libya mission this way (emphasis mine):

Left unaddressed, the growing instability in Libya could ignite wider instability in the Middle East, with dangerous consequences to the national security interests of the United States.

Yesterday, on Meet the Press, Defense Secretary Robert Gates said this to David Gregory:

MR. GREGORY: Secretary Gates, is Libya in our vital interest as a country?

SEC’Y GATES: No. I don’t think it’s a vital interest for the United States, but we clearly have interests there, and it’s a part of the region which is a vital interest for the United States.

A number of folks, particularly on the right, are claiming that Gates contradicted Obama here. It seems to me that the question of whether Gates directly contradicted Obama is an overly narrow one, and not that easy to answer, given the vagueness of Gates’s overall quote.

But Gates’s claim is nonetheless significant, because it does highlight the weakness of Obama’s claim that the Libya mission was essential to defend our national security. The crucial context here is that Obama has been taking criticism from both parties, particularly Democrats, for not getting Congressional authorization for military operations in Libya, and that the claim that acting was necessary for our national security interests is the primary justification under the War Powers Resolution for not seeking that Congressional authorization.

The phrase “vital interest” is vague, but it’s hard to see how the mission in Libya can have been necessary to avert “dangerous consequences” to our national security interests while simultaneously not being “in our vital interest as a country.” So Gates’s quote gives a weapon to Democrats (and Republicans) who are arguing that Obama should have sought Congressional authorization before ordering military action. While there may be plenty of good reasons for doing so, Gates’s quote is significant, in that it implicitly reveals the absurdity of using the claim of urgent national security imperatives to justify it.