Whether or not the ceasefire with Iran holds, and whether or not Iran keeps its uranium stockpile and enrichment program, one thing is clear: nuclear dangers are growing.
The Trump administration’s last round of threats against Iran was widely received as nuclear saber-rattling . U.S.-Israeli air strikes near Iran’s Bushehr nuclear power plant drew a Russian warning about escalation with “ irreparable consequences .” Nuclear norms and guardrails are eroding, and actual nuclear threats are re-emerging.
The war in Iran has made nuclear proliferation more likely, not less. Clearly, if Iran had nuclear weapons, it would not have been attacked. That’s a powerful object lesson for other countries in why they might want to pursue nuclear weapons themselves.
The United States claims that its purpose in Iran was preventing nuclear proliferation. Meanwhile, pundits writing in prestigious publications are advocating what they call “selective proliferation,” where more U.S. allies go nuclear. If Germany and Japan developed their own independent nuclear deterrents, their argument goes, they could shoulder more of their own defense burdens, strengthen regional stability, and reduce their reliance on an increasingly unpredictable United States.
This is beyond farcical and dangerously misguided. It is strategic amnesia at best, sleepwalking into Armageddon at worst. European leaders are discussing new forms of nuclear cooperation using their existing nuclear arsenals. France and Germany have already taken concrete steps toward structured nuclear deterrence coordination , reflecting uncertainty about long-term reliance on U.S. guarantees.
But encouraging even “responsible” allies like Germany to acquire their own nuclear weapons would not stabilize the system or make Europe or other regions more secure. It would increase the risk that conventional conflicts could spiral into nuclear ones. Recent hostilities between Pakistan and Afghanistan demonstrate how quickly regional tensions can escalate in proximity to nuclear-armed states.
“Selective proliferation” would loosen foundational legal and political frameworks that constrain nuclear risks. It would complicate alliance dynamics and make miscalculations, system failures, crisis escalation, and using nuclear weapons more likely.
The problem is not just who possesses them; it’s the inherent complexity and fragility of nuclear systems themselves. The greatest danger may not be irrational leaders or unstable regimes, but compressed decision timelines, imperfect information, technological vulnerabilities, and the ever-present risk of human error in all nuclear systems.
“Selective proliferation” advocates cite the Cold War as evidence that nuclear deterrence can be safely managed and sustained over time. But that ignores how close the world faced disaster on multiple occasions. From the Cuban Missile Crisis to false alarms in early warning systems , history is replete with warnings. Near misses occurred not because leaders sought nuclear war but because complex nuclear systems failed under pressure.
Adding more nuclear-armed states—even highly capable, stable ones—would multiply those risks and fundamentally alter alliances in ways that would undermine, not strengthen, nuclear deterrence. Alliances function not only through capabilities but through coordination, communication, credibility, and clarity of command. “Selective proliferation” would complicate those functions.
Effective deterrence hinges not on the number of nuclear warheads or nuclear-armed states, but on allies’ ability to manage conditions of extreme uncertainty. Each additional nuclear actor introduces new command-and-control systems, new decision-making, new potential points of failure. Greater complexity means greater potential for misunderstanding and escalation in a crisis.
Hoping that all this can be managed safely is not a strategy. Would newly nuclear-armed allies act independently in a regional conflict? How would escalation be managed across multiple nuclear decision centers? Could adversaries exploit ambiguity within alliances to sow division or miscalculation? Uncertainty surrounding these questions would weaken deterrence.
“Selective proliferation” would violate the Nuclear Nonproliferation Treaty (NPT), whose foundational bargain is that non-nuclear states agree not to pursue nuclear weapons while nuclear-armed states commit to negotiating in good faith toward nuclear disarmament. That bargain has always been imperfect and contested, but nonetheless it remains one of the most important international security guardrails.
Today, it is under growing strain . Confidence in the long-term commitment of nuclear-armed states to their treaty obligations is eroding. Progress toward disarmament has slowed. The modernization of nuclear arsenals continues. These stresses will be front and center at the 2026 NPT Review Conference . Calls for “selective proliferation” will only aggravate them.
Proponents of “selective proliferation” are confident it wouldn’t trigger broader proliferation, but that confidence is misplaced. Nuclear decisions aren’t made in a vacuum. Rather, they are formulated amid regional security dynamics, historical rivalries, and differing perceptions of threat. Germany or Japan acquiring nuclear weapons would prompt South Korea, Poland, and other states to reconsider their non-nuclear status. Proliferation pressures in the Middle East, already acute, would escalate.
“Selective proliferation” is presented as a pragmatic response to a changing world. In reality, it’s the opposite: an indication of failure to reckon with the reality of nuclear threats.
The international community has preserved stability in the nuclear age despite extraordinary risks, often by luck as much as design. Adding more nuclear-armed states increases the probability that those risks will one day materialize. The goal of international security policy should not be to manage a world with more nuclear weapons but to prevent such a world from emerging.
The post More Nuclear States Is Not a Recipe for Greater Security appeared first on Foreign Policy In Focus .