AP Photo

Dear Ambassador Hill,

Congratulations on your long-delayed confirmation as U.S. ambassador to Iraq. By now you're probably on the ground in Baghdad, being overwhelmed with briefings from the embassy staff and the military. We trust that Iraqi Prime Minister Nouri al-Maliki and his government have also presented you with their agenda for what Iraq wants from the United States. You are being pulled in many different directions, with everyone vying to attract your attention to their own special needs and issues.

Iraq is sure to test your formidable diplomatic skills. The ad hoc bargains and ceasefires negotiated by your predecessor, Ryan Crocker, and the U.S. military -- deals that kept the country from plunging deeper into the throes of insurgency and civil...