SEOUL -- It was inevitable that Korea, at some point, would rear its complicated head as a campaign issue. In a speech to the Veterans of Foreign Wars convention, Democratic presidential candidate Sen. John Kerry said the withdrawal of 12,000 of the 37,000 U.S. troops stationed in South Korea would destabilize the Peninsula "at the very time we are negotiating with North Korea, a country that really has nuclear weapons."

Every U.S. president from Harry Truman to George W. Bush has found the Korean problem to be tough. America's precipitous withdrawal in 1949 to husband scarce military resources helped invite a North Korean attack the following year when the United States failed to make its intentions clear and seemingly wrote South Korea off. In the post-Korean War period, President Jimmy Carter stirred up a hornet's nest of opposition with his plan to withdraw U.S. forces, reversing course only when intelligence was found to have underestimated the strength of the North Korean Army by 25 percent.

History hangs no heavier than on the Korean Peninsula, where U.S. forces serve multiple roles: deterring the North, defending the South and providing a measure of regional stability in what has always been a tense region with multiple historic rivalries among China, Russia and Japan. But today, in addition to underscoring the half-century American security commitment to South Korea, U.S. forces help nurture a still fragile reconciliation between the two Koreas as well as underpin negotiating efforts with the North.