by Prof. Zafar Nawaz JASPAL•Published on November 24, 2025

Source: Wikipedia, Mushroom cloud from the explosion of Castle Bravo, the largest nuclear weapon detonated by the US, in 1954

PRESIDENT Trump has repeatedly called for renewed US nuclear weapon testing.

Though he claimed—incorrectly—that the US will resume testing due to China, Russia, North Korea and Pakistan’s clandestine nuclear tests, he is interested in advancing his country’s nuclear arsenal as part of Washington’s drive for significant changes in its military. Vice President JD Vance and some Republicans in Congress endorsed Trump’s determination to resume nuclear testing. Indeed, the US resumption of nuclear testing could be a harbinger of a new era of international nuclear politics, a development of grave significance. Hypothetically speaking, the new era’s first casualty could be the demise of the 20th-century nuclear non-proliferation regime (NNPR), an increasing number of nuclear-armed states, fabrication and integration of emerging destructive technologies to advance the lethality of the nukes, recalibration of nuclear doctrines influenced by a multipolar strategic environment, discredit of nuclear-taboo and amplifying nuclear risks due to accidents and inadvertent use of nuclear weapons. This could lead to a significant shift in the global nuclear stability, potentially increasing the risk of nuclear conflict.

The NNPR regime has played a pivotal role in nuclear arms control, effectively institutionalizing extended nuclear deterrence to prevent the latent nuclear-weapon states from developing their own indigenous nuclear deterrence potential. However, the rapid transformation in the global strategic environment is now posing challenges, particularly in weakening the trust of three key nuclear technologically advanced states—Japan, South Korea and Germany—in extended deterrence and contemporary international nuclear order. Japan is relying on the US extended nuclear deterrence security arrangement. Last week, the Japanese Prime Minister Sanae Takaichi hinted at a shift in the country’s three non-nuclear principles, i.e., not to possess, produce or introduce nuclear weapons into its territory. Currently, Tokyo is worried due to the expansion of China’s nuclear arsenal. On November 10, 2025, she hinted in parliament about the possibility of altering those three principles in an upcoming revision of Japan’s security strategy. She believed that the non-introduction principle is not realistic. Therefore, the US should be allowed to bring nuclear weapons into Japan, on submarines or other platforms, to strengthen deterrence. Even a minor shift in the nuclear policy ends Japan’s moral opposition to the nukes and strengthens the nuclear optimist (though ineligible today) perception in the country. It will be apparent that there is distrust of the contemporary international nuclear order.

South Korea, despite having full fuel cycle capability, has refrained from developing indigenous nuclear deterrence. Like neighbouring Japan, South Korea is protected under Washington’s so-called nuclear umbrella. This term refers to the protection that the US provides to its allies by promising to use its nuclear weapons to defend them in case of a nuclear attack. Recently, Seoul and Washington signed a deal to build and deploy a nuclear-powered submarine, enhancing the South Korean navy’s capabilities. The justification for nuclear-powered submarines is that they provide greater underwater endurance and stealth potential. Notably, without nuclear weapons, a nuclear-powered submarine could not balance a North Korean nuclear-armed Navy. Therefore, the overwhelming majority of South Koreans have expressed their desire to develop the country’s own nuclear capability in various polls. The transformation of nuclear politics because of the resumption of testing by nuclear-armed states further strengthens the demand for nuclear weapons in South Korea.

Germany possesses the scientific and technical capability to produce nuclear weapons, but it has refrained from developing an indigenous nuclear deterrence capability. The protracted Ukrainian war and President Trump’s approachto European security arrangements have a decisive impact on Berlin’s strategic thinking. German Chancellor Friedrich Merz has been discussing a European nuclear umbrella with the United Kingdom and France. The UK and France are incapable of extending their nuclear deterrence to other European countries, including Germany. Merz strives for a European-led nuclear protection in the emerging new era of nuclear politics, which could end Berlin’s nuclear non-proliferation policy. The great powers’ strategic competition and new aspirants of nuclear weapons could undermine the over-seven-decade consensus on nuclear weapons that centres on balancing and deterrence, which tends to downplay the prospect of an actual nuclear exchange. Nuclear optimists and deterrence theorists tell a story about prospective Armageddon aimed, through their telling, to make actual nuclear war unthinkable.

The new trends in global geopolitics are increasing the prospect of nuclear catastrophe because President Trump, President Putin, Prime Minister Netanyahu, Prime Minister Modi and Chairman Kim Jong Un seem likely to do the unthinkable to pursue their strategic objectives. Furthermore, the new emerging destructive technologies are not only increasing the risks of misjudgment, organizational failure and technical error, but also significantly raising the potential for nuclear accidents and inadvertent use of nuclear weapons, a prospect that should deeply concern us all. To conclude, the resumption of nuclear testing by the US will trigger a dangerous chain reaction of testing, entailing a dangerous new era of nuclear politics or the fourth nuclear age. This potential chain reaction should underscore the urgency of the situation, as in the fourth nuclear age, warfare will feature increased reliance on nuclear weapons.

Prof. Zafar Nawaz JASPAL

Prof. Zafar Nawaz JASPAL, Nonresident Fellow at MEPEI, is an Islamabad-based analyst and meritorious professor of International Relations at SPIR, Quaid-i-Azam University and an advisory Board Member of the Institute for East-West Strategic Studies (RIESS), affiliated with Oxford University, U.K. E-mail: jaspal_99@hotmail.com, X: @zafar_jaspal