Demystifying the Nuclear Threshold

Ariel (Eli) Levite and Toby Dalton| Carnegie Endowment for International Peace

The nuclear weapons threshold is increasingly important for proliferation strategy and policy. Policymakers should better understand the implications of the threshold phenomenon in the current international security environment and plausible strategies to deal with the growing challenge that it presents. … This essay argues that a nuclear threshold represents a distinct analytic category of interest that is increasingly important for proliferation strategy and policy. Regardless of whether a state consciously pursues a nuclear threshold capability as an end result, as a trial balloon, or as a temporary holding pattern before proceeding to nuclear weapon possession—as its original or evolved intention—it constitutes a far more robust posture than meets the eye. Moreover, the pursuit of the nuclear threshold unleashes a unique set of dynamics that have serious operational, political, strategic, and often geopolitical implications. Among these dynamics are profound dilemmas that will confront policymakers in states that may feel compelled to respond to a threshold aspirant’s advances.

Australia agrees to sell uranium to India, ending a long stalemate

Charlotte Graham-McLay | Japan Today

Australia will begin to sell uranium to India for peaceful purposes after the two countries' leaders signed an administrative deal Thursday, enacting an agreement on exports of the material that was held up for years over concerns about weapons use. Australia's Prime Minister Anthony Albanese and India's Prime Minister Narendra Modi made the joint announcement after a meeting in Melbourne. The leaders didn't immediately supply details of how much uranium would be sold, or when. Exports of Australian uranium to India stalled after an agreement to do so in 2014, because of concern that the material could be used to make weapons. Australia has the world's largest known uranium resources, but the country doesn't use any nuclear power or weapons and all uranium is exported. India, which has a population of 1.4 billion people and a growing middle class, wants to install 100 gigawatts of nuclear power by 2047 — enough to power nearly 60 million Indian homes a year. But obtaining uranium hasn’t been simple.

Trump downplays Iran’s nuclear threat as ceasefire collapses

Kevin Breuninger and Chloe Taylor | CNBC

President Donald Trump on Wednesday said Washington’s ceasefire with Iran is over, and threatened more military action, after the two sides clashed overnight. Trump, in a flurry of remarks during numerous press events on his final day at the NATO summit in Ankara, Turkey, also signaled the U.S. would reimpose its naval blockade in the Strait of Hormuz. Later, he seemed to downplay the nuclear threat posed by Iran, while ruling out the need for any U.S. troops on the ground in the country. “We’ve already got the nuclear material because it’s so far underground, nobody’s going to be able to get it except us, because we have the equipment that can get it,” Trump told reporters during a meeting with Syrian President Ahmed al-Sharaa, referring to the aftermath of U.S. attacks on Iranian nuclear sites last year. The nuclear assessment marked a pivot from his justification for the Iran war, which he began Feb. 28. Trump has cited his concern that Iran was on the brink of developing a nuclear weapon for continuing the conflict.

Heat Wave Threatens Output at Five French Nuclear Reactors

Will Mathis and Joe Wertz | Bloomberg

France’s latest heat wave is straining the country’s power system, with Electricite de France SA warning that as many as five nuclear plants could face output curbs in the coming days as soaring temperatures affect rivers used for cooling. EDF is set to reduce production at two reactors this week, the first of a series of potential curbs as extreme heat spreads across Europe. France’s nuclear fleet is the backbone of the region’s power system, supplying low-carbon electricity that is routinely exported to neighbors including Germany and the UK. … Repeated bouts of really hot temperatures are increasing the risk of further disruption to the power system, according to Alessandro Armenia, an analyst at Kpler. With little time for rivers to cool between hot spells, each successive heat wave raises the risk of nuclear output restrictions, even if temperatures don’t surpass those seen earlier this summer, he said.

MIT researcher proposes a way to detect nuclear weapons in space

Zach Winn | MIT News

The 1967 Outer Space Treaty bans the placement of nuclear weapons in space, but there’s currently no way to verify satellites don’t contain nuclear weapons. In fact, no verification methods have even been proposed in unclassified, peer-reviewed literature. Now, MIT Professor Areg Danagoulian is proposing a way to determine if a satellite orbiting Earth contains a nuclear weapon. In a new paper published in Nature, Danagoulian describes his idea for a satellite-based sensor system that could orbit close by a suspect satellite and detect neutrons generated by high-energy protons colliding with radioactive material. In the paper, Danagoulian calculates that a sensor system the size of a large encyclopedia could detect a nuclear weapon with 99 percent accuracy if it orbited within 4,000 meters of the suspect satellite for about a week. He also estimates that the detection time could be cut to a matter of hours if multiple satellite sensors were used or the sensor satellite was able to get within 1,000 meters of the suspect satellite

Chinese nuclear weapons, 2026

Hans M. Kristensen, Matt Korda, Eliana Johns, Mackenzie Knight-Boyle | Bulletin of the Atomic Scientists

Within the past decade, China has significantly expanded its ongoing nuclear modernization program by fielding more types and greater numbers of nuclear weapons than ever before. Since our previous edition on China in March 2025, China has continued to develop its three new missile silo fields for solid-fuel intercontinental ballistic missiles (ICBMs), continued the construction of new silos for its liquid-fuel DF-5 ICBMs, has been developing new variants of ICBMs and advanced strategic delivery systems, and has likely produced excess warheads for these systems once they are deployed. China has also further expanded its dual-capable DF-26 intermediate-range ballistic missile force, which appears to have completely replaced the medium-range DF-21 in the nuclear role. At sea, China has been refitting its Type 094 nuclear-powered ballistic missile submarines (SSBNs) with the longer-range JL-3 submarine-launched ballistic missile, and is building additional Type 094 SSBNs as well as a new class known as Type 096. In addition, China has recently reassigned an operational nuclear mission to some of its H-6 bombers with an air-launched ballistic missile that might have nuclear capability. To what extent this expansion will affect China’s nuclear policy and strategy for using nuclear weapons remains to be seen.