South Korea is facing a growing danger of nuclear decoupling: the possibility that North Korea could use its capability to threaten US cities to make Washington hesitate before defending Seoul.

As North Korea accumulates its nuclear arsenal—as of July 2026, the DPRK is estimated to possess 60 to 100 nuclear weapons—and develops intercontinental ballistic missiles (ICBMs), such as the Hwasong-18, that could reach the continental United States, Pyongyang might increasingly believe that it could weaken the U.S.-ROK alliance. If the current trend continues, a North Korean leader might at some point calculate that a US president would be reluctant to risk Los Angeles or New York to protect Seoul.

The key objective of such a strategy would not necessarily be to initiate a large-scale nuclear war. Instead, North Korea could politically isolate South Korea by using nuclear blackmail, restrict Seoul’s military options, weaken public confidence in the alliance, and ultimately force Seoul to negotiate alone.

Such a risk is contributing to growing support in South Korea for an independent nuclear capability—80 percent of South Koreans favored an indigenous nuclear weapons capability according to a poll conducted this year. Nevertheless, nuclear development incurs serious diplomatic, economic, technological, and alliance-related costs. Meanwhile, the United States has been unsupportive of redeploying tactical nuclear weapons to the Korean Peninsula.

Israel Offers Useful Lessons to South Korea

Unlike South Korea, Israel is not protected by a formal US extended deterrence guarantee. Although Washington provides a wide range of support to Israel and repeatedly affirms its commitment to Israel’s security, the United States has not publicly promised to carry out nuclear retaliation on behalf of Israel.

Israel has instead combined American support with strong conventional forces, a multi-layered missile defense architecture, an independent intelligence capability, indigenous arms production, national resilience, and the ability to act without waiting for another country’s authorization.

To be sure, South Korea cannot simply adopt the model. Israel is widely understood to possess an undeclared nuclear capability, whereas South Korea is a treaty ally of the United States and a non-nuclear member of the NPT. The two countries’ geographical and strategic circumstances also differ.

Nonetheless, Israel demonstrates how a close American partner could avoid fully relying for its security on Washington’s willingness to escalate.

Preserving the Capacity to Act Independently

The first lesson of the Israel case is that an alliance commitment should complement, not replace, a nation’s military capacity.

Israel’s conventional superiority has historically offered options that could be used below the nuclear threshold. Its value lies not only in its........

© The Times of Israel (Blogs)