Why South Korea Should Go Nuclear
South Korea has long relied on the United States to keep the North Korean nuclear threat at bay. Pyongyang began taking fitful steps toward a nuclear weapon during the Cold War, tested its first bomb in 2006, and today regularly issues nuclear threats against its southern neighbor. Seoul, meanwhile, shelters under the American nuclear umbrella that came with the defense alliance it signed with Washington in 1953, just after an armistice effectively ended the Korean War. For decades, this arrangement provided South Korea sufficient security assurance. But today, that assurance appears increasingly fragile.
South Korea’s problem is twofold. First, North Korea’s capabilities are growing. Pyongyang has developed an intercontinental ballistic missile, which raises doubts about whether the United States would honor its alliance commitment and fight for South Korea, because North Korea can now strike American cities with a nuclear weapon. Second, Donald Trump, who has harshly criticized the U.S.–South Korean alliance in the past, is set to begin his second term as U.S. president. Under Trump, the likelihood that Washington would intervene in a conflict on the Korean Peninsula will drop further still.
In such a conflict, Pyongyang would almost certainly threaten nuclear attacks on American targets to deter U.S. participation. U.S. bases in the Asia-Pacific, Guam, or Hawaii would be threatened first, and then the U.S. mainland. This raises the potential cost of American assistance to South Korea far higher than it has ever been. And it is likely enough to make the United States hesitate before getting involved. Consider the war in Ukraine, where Russian nuclear threats have successfully limited U.S. support for Kyiv. If Moscow’s threats worked against the alliance-friendly President Joe Biden, then Pyongyang’s will very likely restrain the nationalist, transactional Trump. South Korea would then be left to fend for itself. To close this glaring gap in its security, Seoul is now considering a step that, until recently, was discussed only on the country’s political fringe: building its own nuclear weapons.
