The Obama administration's ambassador to Iraq may be a star diplomat, but he's not a Middle East expert, Robert D. Kaplan points out in an Atlantic dispatch. Christopher R. Hill, appointed in February, had moved adroitly from the Balkans to negotiations with North Korea before assuming the new post, but Arabs have their own cultural and linguistic mores that preclude diving right in with effectiveness, Kaplan says...and, in that regard, Hill may fall short of his predecessor, the Bush-appointed Ryan Crocker, who is an Arabist by trade. As U.S. troops move out of Iraq, tensions have run high and the situation is sensitive; the U.S. ambassador's ability to broker deals between factions could make the difference between a relatively peaceful Iraq and one engulfed again by civil war. (And the Obama administration passed over a field of others that had more Middle East cred.) Hill will be tested, Kaplan writes; we can only hope he passes.