The free-trade agreement negotiated by the United States and South Korea last week reflects their troubled alliance, in which relations could either be revitalized or unravel over the next six months.

The agreement must be approved by Congress and South Korea's National Assembly, and has generated substantial opposition in both legislatures. The accord is intended to lower tariffs and other barriers to a trade that totaled $78.3 billion last year, with a $13.3 billion surplus in South Korea's favor.

South Korean farmers have taken to the streets in recent weeks to protest the wider opening of their market. Korean automobile companies fear competition from U.S. makers. The agreement is supposed to ensure that Americans can invest in South Korea on par with Koreans, which Americans who have dealt with South Korea contend its bureaucrats will block.

On the American side, the automobile companies and their allies in Congress argue that Koreans will have an unfair advantage because of easier access to the U.S. market. The pharmaceutical industry says it won little under the agreement. And rice growers got nothing because of the political opposition of Korean rice farmers.

On a wider scale, political opposition in South Korea seemed greater than that in America, although President Roh Moo-hyun's approval rating went up a few points after the agreement was signed. Two members of the National Assembly have gone on hunger strike. Said Rep. Chun Jung-bae: "President Roh apparently doesn't consider the loss of economic sovereignty problematic."

Similarly, South Korean newspapers have grumbled that U.S. negotiators bullied Korean officials, and that this was another instance of U.S. domination. The Korea Times asserted last week that the agreement left South Korea vulnerable "to attacks from mighty and well-experienced U.S. traders and lawyers."

Add differences between the Bush administration in Washington and President Roh's government in Seoul over dealing with North Korea, with the U.S. demanding a hard line while Roh seeks to accommodate the North Korean leader, Kim Jong Il. Polls show an anti-American streak among younger South Koreans, who want reconciliation with Pyongyang.

Perhaps nowhere does American frustration with South Korea show up so much as among the U.S. military services. Many officers with experience in South Korea assert that the U.S. should reduce its troops there or perhaps withdraw all but a token force. One who considers that U.S. forces are almost held hostage in South Korea said plaintively: "Let my people go."

U.S. officers point to running quarrels with the South Koreans over issues such as command of U.S. and Korean forces, sharing the cost of U.S. forces in South Korea, U.S. access to Korean training areas, moving U.S. forces to new locations and cleaning up U.S. bases that have been vacated. A particular sticking point: Roh insists on vetoing U.S. deployments out of South Korea to conflicts elsewhere.

Those U.S. forces are needed elsewhere, notably Iraq and Afghanistan. Moreover, most American officers believe that South Korea's forces are capable of defending their country against North Korea with minimal help from the U.S. That is particularly true since the shambles of the North Korean economy has taken its toll on the readiness of North Korea's armed forces.

A small, but indicative, incident reflecting the American attitude: Secretary of Defense Robert Gates came to the Pacific Command headquarters here in late March to attend the assumption of command by Adm. Timothy Keating.

At the ceremony, Gates said the Asia-Pacific region is home to "some of America's oldest and strongest allies."

He said a "great many partnerships — old and new — have grown considerably stronger in recent years. The restoration of military relations with Indonesia comes to mind, as does the strengthening of our longstanding ties with Japan and Australia." Gates did not mention South Korea, a rare omission for an American political leader.

This turbulence may come to a turning point as the South Koreans prepare to elect a new president in December, President Roh being barred constitutionally from succeeding himself. Despite the flood of anti-Americanism on the surface in South Korea, many Koreans and Americans who know South Korea assert that there is a large, if silent, segment of South Korean society that wants to retain their alliance with the United States.

Those Koreans are expected to go public over the next few months and into the presidential campaign season in the fall. South Korea's future relations with America will most likely be a critical issue that will be debated — and then voted on — when the Koreans elect a new president.

Richard Halloran is a Honolulu-based journalist and former New York Times correspondent in Asia. His column appears weekly in Sunday's Focus section.