“Having tactical nuclear weapons back on the peninsula would be clear evidence of our resolve and determination to deter North Korea,” he told Reuters on the sidelines of a forum hosted by the Asan Institute for Policy Studies in Seoul.
“Redeploying the tactical weapons does not preclude South Korea from getting its own capability, but it may give us some time to think about whether we really want to do that,” he added.
The US deployed tactical nuclear weapons in South Korea in 1958 and pulled them out in 1991. It has since vowed to use all of America’s capabilities to defend its key Asian ally.
Yoon had said during the election campaign that he would ask the US to bring nuclear weapons back to South Korea if necessary but backtracked after taking office in May. His defence minister, Lee Jong-sup, said in November that Seoul was not considering such a move.
In an interview with Reuters last week, Yoon said that developing nuclear weapons violates the global nuclear non-proliferation treaty, but that he was working to boost Seoul’s role in US extended deterrence.
Bolton said South Koreans’ doubts about US extended deterrence are “perfectly legitimate” but if it opts to build its own weapons, it would undermine the global non-proliferation regime and trigger a regional nuclear race.
Seoul, Washington and Tokyo could instead explore a trilateral nuclear consultative mechanism similar to NATO’s Nuclear Planning Group, or initiate a broader group of “collective self-defence” that potentially includes Taiwan, he said.
“South Korea can help create a structure of collective self-defence in East Asia or the Indo-Pacific more broadly,” Bolton said. “The more people can look at their mutual interests not simply on the nuclear side but against the threat of states like China and North Korea, the safer we all are.”
