South Korea has long been held up as a model supporter of the global non-proliferation regime, trusting the American “nuclear umbrella” to keep the peace on the peninsula.但首尔周边的战略环境已经发生了巨大变化。朝鲜现在拥有更大、更先进的核武库和导弹武库。 At the same time, confidence in U.S.-extended deterrence has eroded amid American political polarization and doubts about Washington’s willingness to risk its own cities for an ally.The result is something once unthinkable: a serious national debate over whether South Korea needs its own nuclear weapons.这不再是一个边缘想法。 It is a mainstream conversation crossing generational, elite and partisan lines.But while the question is understandable, the answer still isn’t a South Korean bomb.North Korea’s threat and America’s uncertaintyThe core trigger for Seoul’s reassessment is Pyongyang’s rapid weapons development.朝鲜现在部署的短程弹道导弹具有机动性、难以被发现并且能够规避导弹防御。金正恩公开接受了一项原则，即如果该政权感到受到威胁，就允许尽早使用核武器。 That raises the risk of miscalculation in any crisis.At the same time, South Koreans increasingly doubt whether Washington would actually use nuclear weapons on their behalf if doing so invited retaliation on the U.S. homeland.再多的官方保证也无法完全消除这种恐惧。考虑到这种战略组合，韩国人自然会问：我们完全依赖另一个国家的核触发能持续多久？首尔目前的威慑策略限制了韩国的传统战略——所谓的三轴体系——旨在在不发展核武器的情况下对抗朝鲜。杀伤链概念侧重于在攻击即将发生时进行先发制人的打击。韩国防空导弹防御系统提供分层导弹防御，而韩国大规模惩罚和报复系统则威胁毁灭性打击