During the last two years ago, U.S.-South Korea relations have strengthened in ways that many Korea watchers did not expect. With a liberal President Barack Obama entering office, some feared that the new administration’s priorities would differ and relations would clash with the conservative Lee Myung-bak administration. But the two administrations actually worked well together and coordinated closely on a number of regional and global issues, including dealing with North Korea and working toward finalizing the U.S. – Korea free trade agreement. Today, few will deny that bilateral relations are stronger than ever. Looking ahead, however, both Washington and Seoul will need to remain vigilant in nurturing ties. As we look to the second half of the Obama administration, two uncertainties that could potentially complicate bilateral relations need to be carefully watched – namely, 1) the likely shift in Washington’s North Korea policy of strategic patience; and 2) the domestic political wrangling in both countries leading up to the ratification of the U.S.-Korea free trade agreement.