The United States and South Korea last week made the world's largest bilateral free-trade deal. It took 10 months of tough, point-by-point negotiations and officials worked to the very last minute. One measure of the sensitivities in both countries is that, days after the agreement was reached, the official text had not yet been released. Negotiations are only a start: Getting the agreement through both national legislatures promises to be equally, if not more, difficult. Failure in either legislature could strike a body blow to U.S.-South Korea relations.

The economic benefits of a free-trade agreement were always clear. It was estimated that a deal could boost bilateral trade by $20 billion, a nearly 25 percent jump from the two-way trade of $78 billion recorded last year. South Korean exports would increase the most, but both countries would gain substantially. South Korea's exports to the U.S. are expected to rise in the first year alone by 12 percent, or $5.4 billion. Supporters estimate the agreement will create 510,000 new jobs in South Korea over the next decade and help push Korean per capita income past the $20,000 mark toward $30,000. It will transform and modernize the country.

Not all the benefits are monetary. Tariff reductions will oblige South Korea to pursue economic reform, making the economy leaner and better prepared for tough competition from China and Japan. Just as important, the agreement re-balances the U.S.-South Korea relationship, strengthening the economic pillar of an alliance whose resilience has primarily been military based. The bilateral relations have been battered in recent years as the administrations of U.S. President George W. Bush and South Korean President Roh Moo Hyun disagreed -- strongly -- on the appropriate policy toward North Korea. The agreement also strengthens Seoul's hand as it commences negotiations on a trade deal with the European Union later this year.