23 February 2026 — DEFCON Warning System

Diplomatic engagement between the United States and Iran continues amid one of the largest American military buildups in the Persian Gulf in more than two decades. At the same time, North Korea has reaffirmed its reliance on nuclear weapons, Russia and China are adjusting their strategic postures, and formal limits on the world’s largest nuclear arsenals have expired.

These developments are unfolding simultaneously and are reshaping the global nuclear risk environment.

As of 23 February 2026, the DEFCON Warning System remains at Condition Blue (DEFCON 4). There are currently no imminent nuclear threats. However, multiple geopolitical trends warrant heightened monitoring.

U.S.–Iran Talks Continue Under Military Pressure

Informal negotiations between Washington and Tehran over Iran’s nuclear programme have continued in recent weeks, with the next formal round scheduled for early March 2026. Previous discussions in Oman and Doha, mediated by regional and international partners, focused on reducing tensions and clarifying Iranian proposals.

This week, U.S. and Iranian envoys are scheduled to meet in Geneva to review a detailed Iranian response to American demands for limits on uranium enrichment and related activities. The Trump administration has described the current talks as a potential “final diplomatic opportunity,” while several U.S. senators have publicly called for decisive action if negotiations fail.

President Donald Trump has issued an explicit deadline, warning that failure to reach a credible agreement within 10 to 15 days could result in severe consequences. Iranian officials have rejected what they describe as coercive diplomacy, asserting their sovereign right to nuclear research while warning of retaliation against any military action.

Meanwhile, the United States has deployed substantial forces to the region, including two aircraft carrier strike groups, guided missile destroyers, aerial refuelling assets, fighter aircraft, and integrated air defence systems. Analysts describe the current posture as the largest U.S. concentration of airpower in the Gulf since 2003. Former defence officials have stated that the deployment could support a sustained, high-intensity campaign if authorised.

Iran has responded with military exercises and temporary closures of the Strait of Hormuz. Senior Iranian leaders have warned that U.S. naval assets would be targeted in the event of conflict.

Russia, which maintains strategic ties with Tehran, has urged restraint while conducting limited joint naval exercises with Iran in the Gulf of Oman. Moscow has emphasised the importance of diplomacy even as it reinforces its regional presence.

Together, these factors create a complex negotiating environment in which diplomatic efforts are occurring alongside escalating military signalling.

End of New START Removes Major Nuclear Constraint

A major structural shift in global nuclear stability occurred earlier this month with the expiration of the New Strategic Arms Reduction Treaty (New START) on 5 February 2026. The United States and Russia failed to reach a successor agreement, allowing the treaty to lapse.

For more than a decade, New START limited both countries to 1,550 deployed strategic warheads and provided extensive transparency measures, including inspections, data exchanges, and consultative mechanisms. It functioned as the primary framework governing the world’s two largest nuclear arsenals.

With its expiration, no legally binding limits remain in force between Washington and Moscow. Neither government has announced formal negotiations toward a replacement.

Analysts warn that the absence of verified transparency increases strategic uncertainty and may encourage worst-case planning. Without mandated inspections or data exchanges, both sides may assume adversarial expansion, potentially accelerating arms modernisation and stockpiling.

Civil society groups and international organisations have called on both countries to observe previous limits voluntarily and resume negotiations. However, prospects for near-term agreement remain uncertain.

The removal of formal caps represents a significant weakening of the global nuclear risk-reduction architecture.

North Korea Reinforces Nuclear-Centred Doctrine

In East Asia, North Korea has reaffirmed its commitment to nuclear weapons as the foundation of national defence. At its annual party congress, Kim Jong Un was re-elected as general secretary of the Workers’ Party, with official statements emphasising his leadership in strengthening the country’s nuclear forces.

Party communiqués highlighted the integration of nuclear capabilities into conventional force planning, signalling that nuclear weapons will remain central to Pyongyang’s military doctrine. Analysts interpret this as confirmation that denuclearisation is not under consideration.

Shortly before the congress, North Korea unveiled new rocket launcher systems described as capable of delivering nuclear payloads, reinforcing its focus on tactical and battlefield nuclear options.

Diplomatic engagement with the United States has remained stalled since negotiations collapsed in 2019. North Korean rhetoric continues to portray Washington as its primary adversary, framing nuclear forces as essential to regime survival.

From a risk perspective, the consolidation of nuclear doctrine and ongoing military development sustain regional tensions and increase the potential for miscalculation during crises.

Broader Shifts in the Global Nuclear Landscape

Beyond individual flashpoints, recent developments point to broader changes in the international nuclear order.

China’s nuclear posture is receiving increased scrutiny. U.S. officials and allied analysts report that Beijing is expanding its arsenal at an accelerated pace, with some assessments suggesting long-term ambitions for parity with U.S. forces. Unverified claims of undisclosed nuclear testing have also circulated, though these remain unconfirmed.

If substantiated, such testing would mark a significant departure from China’s historical restraint and further intensify strategic competition among major powers.

More broadly, the combination of treaty erosion, force expansion, and technological modernisation suggests that the nuclear system is entering a period of transition. Traditional confidence-building mechanisms and risk-reduction frameworks are weaker than at any time since the late Cold War.

Economic indicators reflect these geopolitical stresses. Oil prices have reached six-month highs amid uncertainty surrounding Middle East tensions, sanctions policy, and trade disputes, illustrating how nuclear-related risk perceptions affect global markets.

Assessment and Outlook

Current developments do not indicate an imminent nuclear conflict. However, the convergence of strained diplomacy, intensified military deployments, weakened arms control structures, and expanding arsenals increases systemic risk.

The U.S.–Iran negotiations represent a near-term focal point, while the absence of U.S.–Russia treaty constraints and North Korea’s hardened posture present longer-term challenges. China’s evolving strategy adds another layer of complexity.

Together, these trends point to a more fragmented and unpredictable nuclear environment.

About the DEFCON Warning System

The DEFCON Warning System is a private intelligence organisation that has monitored and assessed nuclear threats since 1984. It is not affiliated with any government agency and does not represent the alert status of any military branch.

The public is encouraged to make independent assessments and not rely on this organisation for strategic planning. Citizens are urged to familiarise themselves with emergency procedures in the event of a nuclear incident.

In the event of an actual attack, the DEFCON Warning System provides radiation readings based on reported data. Official sources should be consulted for authoritative local information.

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The next scheduled update is at 1 PM on 2 March 2026, with additional briefings issued as conditions warrant.