What breaks first: great-power nuclear stability or Middle East proliferation?
The collapse of US-Russia arms control threatens both strategic stability between great powers and nuclear restraint in volatile regions. The mechanisms differ, the timelines diverge, and the more immediate danger may not be where most analysts are looking.
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The Verification Gap
The last American inspector left Russian soil in August 2023. Russia had suspended participation in New START, the final bilateral agreement limiting strategic nuclear weapons, citing NATO support for Ukraine. When the treaty expired on February 5, 2026, it took with it something more valuable than the warhead limits: the mutual verification regime that had allowed adversaries to peer into each other’s arsenals for half a century.
This matters more than most analysts admit. Strategic stability between nuclear powers has always rested on a paradox: safety through vulnerability. Each side must believe the other could absorb a first strike and still retaliate devastatingly. This requires knowing, with reasonable confidence, what the other side actually possesses. Without verification, that confidence erodes. And when confidence erodes, fingers move closer to triggers.
Yet the conventional framing—that arms control collapse primarily threatens great-power stability—misses the faster-moving danger. The end of the US-Russia framework does not merely destabilize the bilateral relationship. It removes the normative ceiling that has constrained proliferation in Asia and the Middle East for decades. The question is not whether both strategic stability and proliferation cascades are threatened. They are. The question is which breaks first.
The answer, examined carefully, is neither comforting nor simple. Strategic stability degrades slowly, through accumulating uncertainty. Proliferation cascades can ignite suddenly, through a single decision in Tehran or Riyadh. The timelines differ. The mechanisms interact. And the current trajectory suggests the cascade risk materializes first—not because mutual vulnerability is robust, but because proliferation decisions operate on political time while strategic stability erodes on technical time.
The Architecture of Uncertainty
The US-Russia nuclear relationship was never stable in the way its architects claimed. Mutual assured destruction worked not because both sides believed retaliation was certain, but because neither could prove it was not. The verification mechanisms embedded in arms control treaties—on-site inspections, data exchanges, satellite monitoring—served a function beyond counting warheads. They created shared knowledge. They reduced the space for miscalculation.
That space is now expanding rapidly.
Russia maintains approximately 1,550 deployed strategic warheads, the limit New START imposed. Without verification, American intelligence must estimate rather than confirm. The uncertainty cuts both ways. Russia cannot verify American compliance either. Each side must now assume worst-case scenarios about the other’s modernization programs, deployment patterns, and alert postures.
The Congressional Commission on Strategic Posture, reporting in 2023, concluded that the United States faces “two major power adversaries armed with large and diverse nuclear forces” for the first time in its history. China’s arsenal has grown from an estimated 200 warheads a decade ago to over 600 fully operational nuclear warheads today. Pentagon projections suggest continued growth through 2035. Unlike Russia, China was never party to bilateral limits. Its expansion proceeds unconstrained by treaty, unmonitored by agreed verification, and increasingly capable of threatening American second-strike forces.
This creates a structural problem that no amount of diplomatic creativity can easily resolve. The old framework assumed two players. The new reality involves three. Any bilateral deal between Washington and Moscow that ignores Beijing’s arsenal leaves both parties vulnerable to a third-party breakout. Any trilateral framework requires China to accept constraints it has historically rejected. Beijing views its nuclear buildup as achieving parity, not pursuing superiority. From its perspective, arms control would lock in American advantage.
The mechanism of instability here is epistemic rather than material. The warheads exist regardless of whether treaties count them. What changes is knowledge—and with it, the calculations that prevent use. First-strike stability depends on each side believing the other’s retaliatory capability survives an attack. When you cannot verify force structure, you must assume the worst. When you assume the worst, you build more. When you build more, adversaries assume the worst about you.
This spiral has a name: arms race instability. It differs from crisis instability, which concerns incentives to strike first during a confrontation. Both are worsening. Neither will cause immediate catastrophe. The degradation is gradual, measured in years and decades rather than months. Strategic stability between great powers is eroding, but slowly.
The Threshold States
Proliferation operates on different time. A single cabinet meeting can initiate a weapons program. A single test can announce its completion. The decisions that matter are political, not technical. And the political conditions for proliferation in Asia and the Middle East have never been more favorable.
Start with Iran. The International Atomic Energy Agency’s reporting leaves little ambiguity about capability. As of August 2024, Iran’s stocks of enriched uranium and its centrifuge capacity combined are sufficient to make enough weapon-grade uranium for nine nuclear weapons in one month. Iran is a threshold state in the most literal sense: it possesses the fissile material and technical knowledge to build weapons. The only barrier is the decision to do so.
That decision has not been made. Or rather, it has been deferred. Iran’s leadership calculates that overt weaponization would trigger military strikes, sanctions escalation, and regional isolation. The current posture—latent capability without declared weapons—provides leverage without consequence. But this calculation depends on assumptions that may not hold.
The collapse of the JCPOA removed the verification mechanisms that constrained Iranian enrichment. The end of the broader arms control framework removes the normative pressure that made nuclear restraint the international default. If the great powers abandon their own constraints, why should regional powers accept limits?
Saudi Arabia has been explicit. Crown Prince Mohammed bin Salman stated publicly that if Iran develops nuclear weapons, Saudi Arabia will follow. This is not bluster. The kingdom has invested in nuclear infrastructure, cultivated relationships with Pakistani nuclear scientists, and explored uranium enrichment capabilities. The pathway exists. The trigger is Iranian.
Turkey presents a different case. Ankara hosts American nuclear weapons under NATO sharing arrangements but has periodically questioned whether this provides adequate security. President Erdoğan has publicly mused about Turkey’s nuclear options. The country possesses advanced missile capabilities and growing nuclear expertise. A Turkish decision to pursue independent weapons would fracture NATO’s nuclear architecture and trigger cascading responses across the Eastern Mediterranean.
Egypt, historically a leader in Arab nuclear diplomacy, watches both rivals carefully. Cairo’s calculation involves not just Iran but the regional balance of power that an Iranian or Saudi weapon would create. The UAE, despite signing the Abraham Accords and deepening ties with Washington, maintains its own hedging options. The proliferation dynamics in the Middle East are not linear. They are networked. One decision triggers many.
The Asian Calculus
Northeast Asia presents an equally unstable configuration, though the mechanisms differ. Japan, South Korea, and Taiwan are threshold nuclear powers by virtue of their civilian nuclear programs. Each possesses the technical capability to develop weapons within months to years. Each has chosen not to. That choice rests on American extended deterrence—the promise that Washington will defend allies with nuclear weapons if necessary.
This promise is losing credibility.
The problem is not American capability but American commitment. Extended deterrence requires allies to believe the United States would risk nuclear war with China or North Korea to defend them. As China’s arsenal grows toward parity with America’s, that belief becomes harder to sustain. Why would Washington trade Los Angeles for Tokyo? The question is not new. What is new is that Asian publics are asking it openly.
South Korean polling consistently shows majority support for indigenous nuclear weapons. The cumulative effect of North Korean provocations—missile tests, nuclear advances, rhetorical threats—has shifted public opinion decisively. Dissatisfaction with US extended deterrence drives this sentiment. Each North Korean test that goes unanswered erodes confidence that America will respond when it matters.
Japan’s situation is more complex. The country’s collective trauma from Hiroshima and Nagasaki created what scholars describe as nuclear latency functioning as a quasi-religious resource—abstention from weapons as moral identity rather than strategic calculation. This restraint has held for eight decades. It is not guaranteed to hold for eight more.
The structural pressure is straightforward. China’s conventional military superiority in the Western Pacific grows annually. North Korea’s nuclear arsenal expands. American attention divides between Europe, the Middle East, and Asia. Japanese strategists increasingly question whether conventional deterrence suffices and whether American nuclear guarantees remain credible. The taboo against nuclear weapons remains powerful. But taboos can break.
Taiwan occupies the most precarious position. The island cannot rely on formal alliance commitments because the United States does not formally recognize it as a state. American support is deliberately ambiguous. This ambiguity has served deterrence purposes—keeping Beijing uncertain about American intervention—but it also keeps Taipei uncertain. A Taiwanese decision to pursue nuclear weapons would likely trigger the Chinese military action it sought to deter. Yet the alternative—relying on American intervention that may never come—grows less attractive as Chinese capabilities improve.
The Temporal Mismatch
The central insight is temporal. Strategic stability between great powers degrades on a timeline measured in decades. The verification gap widens slowly. Force structures evolve gradually. The calculations that prevent nuclear use shift incrementally. This process is dangerous but not acute.
Proliferation cascades operate on political time. A new government in Seoul could initiate a weapons program within its first year. An Iranian supreme leader’s death could trigger succession struggles that make weaponization attractive to competing factions. A Saudi decision to match Iranian capability could follow an Iranian test by months, not years.
The mismatch matters because it determines which failure mode materializes first. Great-power strategic stability will likely survive the next decade in degraded form. The US-Russia relationship will be more dangerous, the US-China relationship more unstable, but neither will collapse into conflict from arms control erosion alone. The structural factors that prevent great-power nuclear war—the catastrophic consequences of use, the uncertainty about escalation, the absence of existential territorial disputes—remain operative even without verification regimes.
Regional proliferation lacks these buffers. Iran and Saudi Arabia have no shared understanding of strategic stability. Their rivalry is ideological, sectarian, and zero-sum in ways the US-Soviet competition never was. North Korea’s regime survival depends on nuclear weapons in ways that make arms control nearly impossible. The regional conflicts that could trigger nuclear use—a Gulf war, a Korean peninsula crisis, a Taiwan contingency—are more plausible than great-power conflict precisely because the stakes are lower for outside powers.
This produces a counterintuitive conclusion. The collapse of great-power arms control threatens strategic stability, but the more immediate danger is the permission structure it removes for regional restraint. When Washington and Moscow abandon their own constraints, they forfeit the moral authority to demand restraint from others. When verification regimes disappear, the technical infrastructure for monitoring regional programs atrophies. When the NPT’s grand bargain—disarmament by nuclear states in exchange for non-proliferation by others—visibly fails, the bargain’s beneficiaries reconsider their end.
The Cascade Mechanics
A proliferation cascade requires a trigger and a transmission mechanism. The trigger is most likely Iranian. Tehran’s threshold status is unstable. Domestic politics, regional dynamics, or great-power confrontation could push the regime toward overt weaponization. The transmission mechanism runs through Gulf capitals, where security establishments have prepared contingency plans for exactly this scenario.
Saudi Arabia’s pathway is the most developed. The kingdom has invested in ballistic missile capabilities, nuclear infrastructure, and relationships with nuclear-capable states. Pakistan’s nuclear program received Saudi funding; the relationship creates options. A Saudi decision to pursue weapons would not require starting from zero. It would require activating existing preparations.
The UAE and Egypt would face immediate pressure to respond. Neither wants to be the only non-nuclear power in a nuclearizing region. Both have the technical foundations to develop programs. The cascade logic is self-reinforcing: each new nuclear state increases pressure on remaining non-nuclear states to follow.
Turkey’s position complicates the picture. Ankara’s NATO membership provides nuclear protection through alliance sharing arrangements. But Turkish-American relations have deteriorated, and Erdoğan’s government has questioned whether NATO commitments remain reliable. A Turkish decision to pursue independent weapons—triggered by regional proliferation or alliance doubts—would create a secondary cascade affecting Greece, potentially Egypt, and the broader Eastern Mediterranean.
In Asia, the cascade mechanics differ. The trigger is more likely to be a dramatic failure of extended deterrence than a single state’s weaponization. A Chinese military action against Taiwan that America fails to prevent. A North Korean strike that goes unanswered. A visible American withdrawal from regional security commitments. Any of these could shatter the assumption that American protection substitutes for indigenous nuclear capability.
Japan and South Korea would face simultaneous pressure. Their security situations are linked: a Japanese decision to nuclearize would increase South Korean incentives, and vice versa. Taiwan’s options are more constrained—weaponization would likely trigger Chinese intervention—but the island’s strategic calculations would shift dramatically if its neighbors acquired independent deterrents.
The Intervention Points
Three leverage points exist, though none is easy to activate.
First, the verification architecture can be partially preserved even without bilateral treaties. The IAEA’s safeguards system, the Comprehensive Nuclear-Test-Ban Treaty Organization’s monitoring network, and national technical means provide continued visibility into nuclear programs. Strengthening these mechanisms—through increased funding, expanded access, and technological upgrades—cannot replace bilateral verification but can maintain some transparency. The cost is modest: perhaps $500 million annually across relevant organizations. The political will is the constraint.
Second, regional security architectures can substitute partially for great-power arms control. In Asia, this means deepening alliance commitments through concrete capabilities rather than rhetorical assurances. Nuclear sharing arrangements—stationing American weapons on allied territory under dual-key control—would demonstrate commitment more credibly than statements. The trade-off is escalation risk: forward-deployed weapons are more vulnerable and more provocative. In the Middle East, the equivalent would be security guarantees to Gulf states conditional on non-proliferation commitments. The trade-off there is entanglement: America would be committing to defend regimes it has historically kept at arm’s length.
Third, direct engagement with threshold states can extend decision timelines. Iran’s calculation depends on the costs and benefits of weaponization. Sanctions relief, security assurances, and regional integration could shift that calculation—but only if offered credibly and enforced consistently. The JCPOA’s failure demonstrated the limits of agreements that domestic politics can reverse. Any successor arrangement must address this vulnerability. The trade-off is legitimization: negotiating with Iran rewards its nuclear progress and may encourage other states to pursue similar leverage.
None of these interventions prevents the underlying dynamic. Arms control has collapsed. Strategic stability is degrading. Proliferation pressures are intensifying. The best achievable outcome is managed decline: slowing the erosion, extending the timelines, creating space for future arrangements that current politics cannot produce.
The Likely Trajectory
The most probable scenario through 2035 involves continued great-power strategic stability—degraded but functional—alongside one or more regional proliferation events. Iran is most likely to cross the threshold first, whether through overt testing or accumulated capability that makes the distinction meaningless. Saudi Arabia follows within two to five years. The Gulf cascade then pressures Turkey and Egypt, though neither may complete weapons programs within the decade.
In Asia, the trajectory depends heavily on American domestic politics. Continued commitment to extended deterrence—backed by visible capability deployments and alliance investments—can sustain Japanese and South Korean restraint. Wavering commitment accelerates proliferation timelines. The variable is not Asian but American: what Washington does matters more than what Beijing or Pyongyang does.
Taiwan remains the wild card. A Chinese military move against the island would shatter assumptions across the region. It would also likely occur in circumstances where Taiwanese nuclear weapons could not have prevented it. The island’s strategic situation is tragic: the scenarios where nuclear weapons would help are precisely the scenarios where pursuing them triggers the attack they were meant to deter.
The world that emerges from arms control collapse is not necessarily one of nuclear war. It is one of nuclear anxiety: more weapons, more states, more uncertainty, more risk. The guardrails that previous generations built are coming down. What replaces them will be improvised, incomplete, and inadequate. But it will be something. The alternative—fatalism about inevitable catastrophe—serves no one.
Strategic stability through mutual vulnerability will survive the next decade, wounded but recognizable. Proliferation cascades in the Middle East will likely begin within five years. Asia’s fate depends on choices not yet made in Washington. The first thing to break is not the great-power balance but the regional restraint that balance once underwrote.
Frequently Asked Questions
Q: Why can’t the US and Russia simply negotiate a new arms control treaty? A: The structural obstacles are formidable. Russia has suspended participation in existing frameworks and shows no interest in new constraints while the Ukraine conflict continues. More fundamentally, any bilateral deal ignores China’s growing arsenal, leaving both parties vulnerable to a third-party buildup they cannot verify or constrain.
Q: How quickly could Iran actually build a nuclear weapon? A: IAEA assessments indicate Iran could produce enough weapon-grade uranium for multiple devices within one month. Weaponization—building a deliverable warhead—would require additional time, perhaps six to twelve months. The constraint is political, not technical.
Q: Would Japan really abandon its nuclear taboo? A: The taboo remains powerful but is not absolute. Japanese public opinion has shifted, with polls showing increased openness to discussing nuclear options. A dramatic failure of American extended deterrence—such as an unanswered North Korean attack—could trigger rapid reconsideration. The capability exists; only the decision is lacking.
Q: What would a Middle East proliferation cascade actually look like? A: Most likely, Iranian overt weaponization or acknowledged threshold capability triggers Saudi pursuit of weapons, potentially through Pakistani assistance. UAE and Egyptian programs would follow under intense pressure not to be the region’s only non-nuclear powers. Turkey’s response would depend on its NATO relationship and regional threat perceptions.
The Quiet Unraveling
The arms control architecture that constrained nuclear competition for half a century was never as stable as its defenders claimed. It rested on assumptions—bipolar competition, rational actors, shared interest in survival—that were always partial truths. What made it work was not the treaties themselves but the verification regimes that created shared knowledge and the norms that made restraint the default.
Both are now eroding. The verification mechanisms are suspended or expired. The norms are weakening as great powers abandon their own constraints. What remains is capability without transparency, competition without rules, and regional powers watching their patrons’ example.
The cascade, when it comes, will not announce itself with a single dramatic test. It will emerge from accumulated decisions: enrichment programs that continue past civilian needs, missile developments that exceed defensive requirements, security doctrines that edge toward nuclear options. By the time the world recognizes the cascade, it will be too late to prevent it.
The question posed—what breaks first—has an answer, but not a comforting one. Strategic stability degrades slowly. Proliferation cascades ignite quickly. The former will survive the decade. The latter may not wait that long.
Sources & Further Reading
The analysis in this article draws on research and reporting from:
- IAEA Safeguards and Verification - comprehensive overview of international nuclear monitoring mechanisms
- Hudson Institute analysis of 2024 China Military Power Report - detailed assessment of Chinese nuclear force expansion
- ISIS analysis of IAEA Iran verification reports - technical evaluation of Iranian nuclear capabilities
- SIPRI commentary on New START expiration - European perspectives on arms control collapse
- Vienna Center analysis of Asia’s latent nuclear powers - assessment of threshold state dynamics in Northeast Asia
- American Academy of Arts and Sciences on arms control - scholarly analysis of treaty framework erosion
- RAND Corporation on strategic stability - foundational research on stability concepts
- NTI report on safeguarding nuclear expansion - analysis of verification challenges amid nuclear growth
