There were fears that the departure of South Korean President Lee Myung-bak would mark a deterioration of relations between his country and its security ally, the United States. While his successor, Ms. Park Geun-hye, is a fellow conservative, her approach to key issues and her priorities were likely to differ.

Moreover, a series of issues had proven too contentious to settle and they threatened to roil the alliance. Finally, some worried that the U.S.-South Korea relationship had reached its high-water mark and was just too good to sustain.

Yet her first visit to the U.S. as South Korea's leader, made earlier this month, can only be described as a triumph. Ms. Park had a good meeting with U.S. President Barack Obama.