The Two-Front Nuclear Crisis: Iran, North Korea, and a New Era of U.S. Deterrence

“The Iran–North alliance represents a four-decade-long partnership driven by shared hostility toward the United States, economic needs, and strategic isolation,” Danny Citrinowicz, a nonresident fellow with the Atlantic Council’s Middle East Programs and former head of the Iran Branch in the Research and Analysis Division (RAD) in Israeli defense intelligence, tells The Cipher Brief. “The Iranians need to rearm and prepare for another campaign, which requires additional and fresh thinking regarding the depth of the relationship between Tehran and Pyongyang.”

He also warns that this moment may become an inflection point.

“If Iran seeks to change its nuclear strategy, it could ask North Korea for nuclear bombs or highly enriched material or spare parts for the destroyed nuclear facilities, such as the conversion facility in Isfahan,” Citrinowicz continued. “The potential damage in the event of such an event is so severe that it is essential that the intelligence organizations of the United States, South Korea, and Israel identify signs of this.”

Pyongyang’s Nuclear Threat

Despite UN sanctions and diplomatic efforts, a recent Congressional Research Service (CRS) brief underscored that North Korea continues to surge forward with both nuclear-weapons and ballistic-missile development. For Kim Jong Un, analysts note, nuclear weapons are a guarantor of regime security, and he has no intention of abandoning them.

North Korea’s nuclear doctrine and capability sets are evolving in troubling ways. The 2025 CRS brief states that a September 2023 law expanded the conditions under which Pyongyang would employ nuclear weapons, lowering what had been a high threshold for use. The same report noted the regime “promised to boost nuclear weapons production exponentially and diversify nuclear strike options.”

On the delivery side, the brief outlines how North Korea is fielding solid-fueled road-mobile ICBMs, sea-based launch systems, and pursuing multiple warheads on a single missile — all elements that raise the question not just of deterrence but of crisis stability and escalation control. In short, Pyongyang appears to be reaching toward a survivable deterrent — or perhaps a warfighting capability — that can impose calculations on the U.S. and its allies in a far more challenging way than before.

“Kim’s investment in new nuclear-capable delivery systems reflects the strategic importance of the country’s nuclear arsenal,” Kelsey Davenport, Director for Nonproliferation Policy at the Arms Control Association, tells The Cipher Brief. “North Korea is better positioning itself to evade and overwhelm regional missile defenses and target the U.S. homeland.”

Treston Wheat, chief geopolitical officer at Insight Forward, reinforces that intelligence picture, stressing that open-source assessments now “frame North Korea as a maturing nuclear-warfighting state,” with doctrine “trending toward first-use options in extreme regime-threat scenarios.” He notes that U.S. intelligence already evaluates Pyongyang as having achieved miniaturization: “A 2017 DIA assessment judged DPRK miniaturization sufficient for SRBM-to-ICBM delivery.”

Taken together, those capabilities point to a shifting threat environment for Washington.

“North Korea has tested missiles with the range necessary to target the continental United States,” Davenport underscored. “U.S. military planners have to assume that North Korea can target the United States.”

Need a daily dose of reality on national and global security issues? Subscriber to The Cipher Brief’s Nightcap newsletter, delivering expert insights on today’s events – right to your inbox. Sign up for free today.

Iran’s Nuclear Surge

Meanwhile, Iran is not standing still. Tehran has begun openly emulating aspects of Pyongyang’s nuclear playbook, indicating that if Western strikes against Iranian nuclear infrastructure forced Tehran to go underground, it could adapt quickly. That duality matters: Iran can arguably deploy its program overtly, under inspection and diplomatic cover, but at some threshold, it may decide the only path to survival is accelerated weaponization. If that happens while North Korea is already pushing new strategic capabilities, the U.S. is confronted with two simultaneous flashpoints — one in the Middle East, the other in Northeast Asia.

Deterrence, by definition, demands clarity of purpose, credible capabilities, and correctly calibrated signals. When the U.S. must manage a nuclear-armed North Korea and a near-breakout Iran at the same time, the risk is that strategic bandwidth becomes overstretched.

“Despite the failure of that approach, Iran maintains that its nuclear doctrine is unchanged and it does not intend to pursue nuclear weapons,” Davenport noted. “(But) without a pragmatic diplomatic approach that addresses Iranian economic and security concerns, Tehran’s thinking about nuclear weapons could shift.”

That potential shift in Tehran’s calculus becomes even more concerning when paired with broader warnings about Western inattention.

“If Western focus on the Iran threat dwindles, there is a risk the regime could take a new, covert path to nuclear weapons using remaining or reconstituted assets or foreign help,” Andrea Stricker, Deputy Director of the Nonproliferation and Biodefense Program at the Foundation for Defense of Democracies, tells The Cipher Brief. “Such a lack of focus is similar to how North Korea became nuclear-armed.”

Tehran, experts caution, still retains deep technical capacity.

“Iran retained enough fissile stock and technical expertise to rebuild quickly, meaning the setback was tactical rather than strategic,” Wheat noted.

From Washington’s vantage point, the real danger is a dual crisis hitting at once — an Iranian enrichment surge or strike on its facilities in West Asia, paired with a North Korean missile volley or nuclear test in East Asia. That scenario forces the U.S. into parallel decision-cycles, stretching military, diplomatic, and intelligence resources, straining alliances, and creating openings that adversaries could exploit.

North Korea’s expanding warfighting delivery systems add another layer of risk: limited, precision escalation meant to test U.S. resolve. As the CRS notes, its ballistic-missile testing is designed to evade U.S. and regional defenses, putting American and allied forces at heightened risk. In effect, Pyongyang is developing not only a survivable deterrent but potential coercive leverage — just as Iran’s enrichment trajectory edges closer to a threshold that could trigger a U.S.-led military response.

“The possibility of Pyongyang providing nuclear assistance to Tehran is increasing,” Citrinowicz said. “The United States will need to focus its intelligence on this possibility, with the help of its allies who are monitoring developments.”

But that intelligence challenge intersects with another problem: mounting questions about U.S. credibility.

“President Trump has dealt a serious blow to U.S. credibility in both theaters,” Davenport asserted. “This risks adversaries attempting to exploit the credibility deficit to shift the security environment in their favor.”

U.S. Intelligence and Strategic Implications

Open-source intelligence paints a worrying picture: North Korea may have enough fissile material for perhaps up to 50 warheads, though the accuracy and reliability of delivery remain questions. It also signals Pyongyang’s development of submarine-launched ballistic missiles and multiple-warhead ICBMs. The regime has restored its nuclear test site and is now postured to conduct a seventh nuclear test at a time of its choosing.

The IAEA’s November 2025 report says it can no longer verify the status of Iran’s near–near-weapons-grade uranium stockpile after Tehran halted cooperation following the June 2025 Israeli and U.S. strikes on Natanz, Fordow, and Esfahan.

The last confirmed data, from September, showed Iran holding 440.9 kg of uranium enriched to 60 percent — a short step from weapons-grade and potentially enough for up to 10 bombs if fully processed. IAEA chief Rafael Grossi says most of this material is now entombed in damaged facilities. Moreover, satellite imagery activity around storage tunnels in Isfahan has raised serious red flags. The IAEA further cautions that oversight of this highly-enriched uranium site is “long overdue,” warning that the agency has lost “continuity of knowledge.”

Moreover, before the strikes, the IAEA assessed Iran could produce enough weapons-grade material for one bomb in about a week using part of its 60 percent stockpile at Fordow. Damage to centrifuges has likely slowed that timeline. Still, the larger question is political: whether Iran, under renewed UN sanctions and scrutiny, decides that staying within NPT safeguards costs more than openly moving toward a weapon, particularly if work resumes at undeclared or rebuilt sites.

“The U.S. and Israeli strikes have created a window of respite. What happens next depends greatly on Iran’s will to provoke new Israeli strikes,” Stricker said. “North Korea is a wild card and could provide nuclear fuel, facilities, and equipment to Iran.”

Are you Subscribed to The Cipher Brief’s Digital Channel on YouTube? There is no better place to get clear perspectives from deeply experienced national security experts.

Looking Ahead

For Washington, the takeaway is stark: systems designed to manage one nuclear threat at a time may crumble should two crises flare simultaneously. The U.S. would need tighter allied coordination, faster intelligence sharing, and stronger, more flexible military deployments to cope.

Yet above all, policymakers must anticipate the possibility of simultaneous escalation in different theatres.

In the coming months and years, key indicators will include North Korea’s choice to conduct a seventh nuclear test or field a credible submarine-launched nuclear force, and Iran’s enrichment trajectory or decision to strike a covert breakout path. The U.S. must also watch for signs of cross-coordination between Moscow and Pyongyang, or between Tehran and Pyongyang — though open links remain murky.

From a policy perspective, a dual-front scenario demands updated wargames, an inter-theatre force posture review, and close allied coordination across NATO, the Indo-Pacific, and Middle East partners. Washington must also guard against the “umbrella illusion” — the belief that the same deterrence logic will apply unchanged across two theatres facing two distinct adversaries with differing doctrine, capabilities, and thresholds.

Finally, media and public attention naturally tend to focus on Iran’s progress or North Korea’s missile launches — one at a time. However, deterring two simultaneous nuclear-adversary theatres demands strategic awareness that the world may not be sequentially configured. For the U.S., what happens in one theatre may shape adversary calculations in the other. The risk is that by the time Washington pivots from Iran, Pyongyang — or Tehran — may have forced a new reality.

In this two-front nuclear dilemma, the question is no longer whether to monitor Iran or North Korea, but how the U.S. will deter both at the same time — and whether its strategic framework is ready for that challenge.

Emerging forms of collaboration amplify that challenge.

“More concerning is that North Korea is positioning itself to benefit from Russian expertise and to further refine its missile systems using data collected from Russia’s use of North Korean systems against Ukraine,” Davenport added.

Read more expert-driven national security insights, perspective and analysis in The Cipher Brief because National Security is Everyone’s Business.