On June 6, the House Foreign Affairs Asian Subcommittee will focus its attention on “What’s Next for the U.S.–Korea Alliance?” Experts agree that the bilateral relationship is very strong—perhaps in the best condition it has ever been. This is due to both nations sharing common values of freedom, democracy, and free-market principles. The importance of the alliance forged in blood in the crucible of the Korean War was affirmed after North Korea’s two deadly attacks on South Korea in 2010.

To formalize the crucial economic interdependence, Washington and Seoul implemented the Korea–U.S. (KORUS) Free Trade Agreement this year, which is America’s largest trade agreement in Asia. President Lee Myung-bak has developed close personal friendships with both Presidents George W. Bush and Barack Obama. Lee has pushed his nation to assume a large role on the world stage, a status acknowledged by Seoul’s hosting of the G-20 summit and Seoul Nuclear Summit.

Washington has affirmed strong support of its stalwart ally by deploying 28,500 American service members and pledging all necessary means to defend South Korea. The United States has encouraged South Korea to assume a larger role for its defenses, particularly as it prepares for the 2015 assumption of wartime operational command of its forces, which is currently held by the United Nations Command. Washingtonhas commended Seoulfor a new defense reform plan as well as measures to better respond to North Korean provocations.

Yet, there remains an irritant in the bilateral relationship—one that Congress should focus on. South Korea has again requested that Washington remove restrictions on South Korea’s ballistic missiles. Under the terms of a bilateral agreement with theUnited States,Seoul is precluded from developing any ballistic missile with a range greater than 300 kilometers (186 miles) or a warhead greater than 500 kilograms. The only way for South Korea to reach North Korean targets in the rear areas with ballistic missiles would be to place them along the demilitarized zone, well within range of North Korea’s artillery.

Washington has been reluctant to allow South Korea to extend the range of its ballistic missiles due to concern that doing so would undermine nonproliferation and arms control initiatives or spur an arms race in northeast Asia. But Seoul’s voluntary self-restriction did not prevent North Korea from developing missiles that can reach all of South Korea. Nor did it preventPyongyangfrom selling its missiles to a rogues’ gallery of nations such as Iran and Syria.

The North Korean threat is not an idle one. Pyongyang has deployed 700 Scud ballistic missiles against South Korea, which can carry explosive, chemical, or biological warheads.

In 2010, Pyongyang sank a South Korean naval vessel in South Korean waters and shelled a civilian island, killing a total of 50 citizens. Just this week, Pyongyang repeated detailed threats against President Lee and his defense minister and threatened to annihilate South Korean media critical of the North Korean regime. Pyongyang announced its “army corps, divisions and regiments on the front and strategic rocket forces…have already targeted” the headquarters of three newspapers and four radio stations in the center ofSeoul and provided their geographic coordinates.

South Korean media report that theUnited States is now considering allowingSeoul to extend its missiles to 550 kilometers. Doing so would be an improvement but still insufficient for South Korean defense needs. Instead, America’s critical ally should be allowed to extend its missile range to 800–1000 km (the length of the Korean Peninsula) so it can have a sufficiently robust indigenous military to deter, defend, and defeat hostile North Korean actions.

In articulating South Korea’s need for extended-range ballistic missiles, Lee explained that the 300-kilometer limit “was set many years ago on the assumption fighting would happen around the demilitarized zone….[South Korea now faces] new needs in its defense environment [since] North Korea has missiles and long range artillery that can reach all the way down to Jeju Island.South Korea is in need of expanding its defense posture in case of any contingencies.”

North Korea may choose in the future to use, or threaten to use, Scud missiles to pressure Seoul. An inability to defend against the North Korean missile threat would leaveSouth Koreamore susceptible to North Korean influence. To counter this threat,Seoulshould be allowed to extend its ballistic missile range. Doing so would augment a comprehensive array of South Korean and allied security capabilities to deter and, if necessary, defeat North Korea’s coercive diplomacy and military attacks.