This norm developed under scientific, public, and strategic pressure, leading to the Partial Test Ban Treaty in 1963 and later to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 1996. Although the treaty has not yet entered into force, its global monitoring system has made secret testing nearly impossible, and major nuclear powers have maintained voluntary moratoriums. After the Cold War, computer-based simulations replaced physical tests, further reinforcing the ban.

However, recent global developments suggest that the norm against nuclear testing is increasingly being challenged by nuclear powers. Russia and China have been accused of conducting low-yield nuclear tests: Russia’s primary objective appears to be intimidating the West, while China’s motivation is driven by technical considerations. North Korea has conducted physical tests to verify and enhance the reliability of its nuclear arsenal, but also to demonstrate its progress. Concerns have also emerged over the possibility of the United States resuming testing, especially since the CTBT has not yet been ratified.

Yet, open-source evidence suggesting that Russia, China, or the United States are seriously considering a return to explosive testing remains limited. Most declarations have been conditional threats or made by former officials. Today, nuclear tests and the threat of testing serve diverse strategic purposes. Once primarily focused on technological development and arsenal technical reliability, they have now become instruments of geopolitical pressure and power demonstration.

The international community should remain committed to preventing further explosive nuclear tests. The P5 framework provides a valuable platform for addressing these issues. Non-nuclear weapon states can also take various measures to reinforce the norm against testing, such as isolating norm violators, advocating for strengthening the CTBT’s International Monitoring System (IMS), and globally supporting the CTBTO.