Nuclear Weapon Proliferation

76% of South Koreans believe the nation should develop and deploy its own nuclear weapons to serve as a deterrent.

 Many in the South have been alarmed at the perceived fragility of the security alliance that has tied the US to Seoul since the outbreak of the Korean War in 1950.  Questions have grown about Washington's commitment to the alliance as trade rivalries have increased. 

While in power, President Donald Trump strong-armed Seoul into sharply increasing the amount it paid to keep US troops in the South by threatening to withdraw US forces from the peninsula.

   The US has taken a firmer stance on imports of South Korean electric vehicles and is shifting away from a long reliance on Korean semiconductor manufacturers. 

 "The fact that the US does not subsidize Korean electric vehicles and tries to compete in the semiconductors industry is creating anxiety for South Korea," explained politics Professor Hyobin Lee at Chungnam National University. "South Koreans do not trust the nuclear umbrella provided by the US." She added, "How can we trust someone for protection if they treat us as a competitor?" 

The sense is that if Washington cannot be trusted on trade, then how can Seoul be absolutely certain US forces will be committed in the event of another invasion from the North or a threat to South Korea from China? 

Some are placing their support behind a homegrown nuclear capability. They say it would permit Seoul to rely less heavily on the defensive umbrella provided by the US, enable a drawdown of US military personnel and ensure that South Koreans made decisions for themselves on matters of national security.  The acquisition of nuclear weapons was once a topic for the political fringe but has now become a mainstream element of security discussions.   

Another reason for that support is a concept called "unwanted use theory."  According to the theory, as the credibility of US power and preparedness to use nuclear weapons from bases in South Korea increases, that paradoxically makes the South more of a target for its regional rivals, either as a pre-emptive strike or in retaliation.  

President Yoon Suk-yeol in January said his nation might need to acquire a nuclear capability or, at the very least, play a more active role in managing US weapons that could be reintroduced to the South, seeking a return of tactical nuclear weapons or nuclear sharing.

if South Korea were to try to create its own nuclear deterrent, it would take less than one year to develop a weapon.  Any such decision would also mean Seoul would be abandoning its commitments under the Nuclear Non-Proliferation Treaty

South Korea: Why support for nukes is on the rise – DW – 02/17/2023