So long, Jack Charles L. "Jack" Pritchard dropped one on the Bush administration this week by quitting his job as special envoy on North Korea to join the liberal Brookings Institution, days before the next round of talks on the North Korean nuclear dispute. The implicit message in the abrupt departure was that Mr. Pritchard disagreed with the current policy. The special envoy was viewed within the administration as a "Clintonista" who favored the former president's appeasement approach to North Korea. He even went on the now-infamous October 2000 visit to North Korea by Secretary of State Madeleine K. Albright,...