The foreign service goes limp. As U.S. Ambassador Michael Guest prepares to end his mission to Romania later this year, retrospectives on his service are likely to accentuate the positive. Under his watch, the government in Bucharest remained firmly in the “New Europe” camp: Romania contributed troops to the Iraq War, joined NATO, and was usually strongly aligned with America. But other observers of his tenure paint a less glowing picture, believing that a changing of the guard at the U.S. embassy is long overdue. Guest’s critics charge that his ambassadorship has sent a different message abroad than most Americans...