These various observations bring us back full circle to the question of whether U.S. vital interests are engaged by the Saudi-led intervention in Yemen. The incident as a whole demonstrates, if any demonstration was necessary, that in the Middle East everything is logically and intimately related to everything else. So by defining any part of the Middle East as a vital interest, the United States has effectively conceded that every obscure corner is.

This wasn’t so bad when those obscure corners had the good grace to stay stable—or at the very least only explode one at time. Today with Syria, Iraq, Libya, Yemen, Lebanon, and maybe in the not too distant future Tunisia or Saudi Arabia swirling into instability, it is perhaps time to consider whether the concept of U.S. “vital interests” in the Middle East has been stretched beyond its capabilities to protect them.