May 2026
By Xiaodon Liang

The Department of Defense would buy thousands of intermediate range, ground-launched hypersonic weapons over the next five years under plans described in the Pentagon budget request for fiscal year 2027.

The Army proposes spending $749 million on the Long-Range Hypersonic Weapon in fiscal 2027, down slightly from the $983 million appropriated last year. But strikingly, the service now also says it intends to purchase 4,500 of the intermediate-range missiles through fiscal 2031, at a total cost of $10.1 billion.

Given a current unit cost of roughly $39 million, the Army either expects the weapon’s production cost to improve dramatically or to revise upward its cost estimate in future years.

The service is in the process of purchasing three batteries of ground equipment for the hypersonic weapon, but Army plans call for at least one hypersonic unit to serve with each of the five multidomain task forces. (See ACT, May 2024.) Each battery is capable of launching eight missiles at a time and will be equipped with eight spares.

The first operational battery is “very close” to receiving its full complement of missiles and equipment, the Army general in charge of the hypersonic program, Lt. Gen. Frank Lozano, said to a defense industry conference March 17.

Senior Army officers told Defense Secretary Pete Hegseth during a Dec. 12 inspection at Redstone Arsenal in Huntsville, Ala., that the weapon has a conventional warhead “under 30 pounds” and a range of 3,500 kilometers. The Army’s envisioned role for the missile, according to budget documents, is to destroy anti-access/area denial capabilities, opposing long-range missiles, and “other high-payoff/time-critical targets.”

“Theater combatant commands, in coordination with U.S. Strategic Command, will execute mission planning and target engagement” for the new Army weapon, the Pentagon’s office of the director, operational test and evaluation, reported in its fiscal year 2025 review of the program.

The Navy variant of the same missile, the Conventional Prompt Strike system, would receive $2.1 billion in funding this year, compared with $772 million last year. The service intends to procure a more modest number, 59 missiles, through fiscal 2031.

The variants of the missile share the same Navy-produced two-stage, solid-state booster and a common hypersonic glide body that the two services will produce separately. The services conducted a third successful test of the common missile March 26.

In January, the Navy completed installation of launch tubes for the new hypersonic system aboard the USS Zumwalt, the first ship capable of launching the missile. The weapon will also be integrated with two other ships of the same destroyer class, as well as a newly launched program to build a guided-missile battleship.

Air Force plans for two other hypersonic programs will become harder to track as the service marks intended procurement quantities as “controlled unclassified information.”

The Air-Launched Rapid Response Weapon, a boost-glide missile, would cost taxpayers $798 million in fiscal 2026, up from $496 million last year. The Hypersonic Attack Cruise Missile, a scramjet design, would cost $1.2 billion as it enters its first year of procurement spending, up from $838 million in R&D spending alone last year.

Looking beyond the existing program of record, the Navy and Air Force are also researching how nuclear warhead components perform in a hypersonic test bed. R&D documents indicate plans to perform tests of a warhead fuze in such a test bed in fiscal 2028.

The budget request calls for $49.5 million to fund R&D on a new long-range Air Force weapon, named the Air-Launched Ballistic Missile. It would “mature existing hypersonic weapon technologies,” according to the request.

Testifying before the House Armed Services Committee April 29, Defense Secretary Pete Hegseth also said that the Pentagon is considering a hypersonic follow-on to the nuclear-capable sea-launched cruise missile.

May 2026
By Libby Flatoff

The UN Disarmament Commission (UNDC) suspended its April 6 opening meeting after U.S. objections to the session’s substantive agenda.

The United States refused the inclusion of emerging technology on the agenda and called for the removal of the working group on this topic, saying that the UNDC was not the correct forum to address this topic, according to an April 6 UN press release. The delegation also accused the UN of seeking “centralized governance” within the disarmament framework and opposed this path, the press release said.

The UNDC is a deliberative subsidiary organ of the UN General Assembly, and all 193 member states participate in the dialogue. The April 6-24 UNDC session was intended to be the final one in a three-year cycle.

The commission meets annually and usually concentrates on discussing two agenda items in substantive plenary sessions and working groups. This year, it was meant to continue discussions on “formulating recommendations for achieving nuclear disarmament and non-proliferation of nuclear weapons, as well as fostering common understandings related to emerging technologies in the context of international security.”

After the United States voiced its objections, the UNDC moved into informal consultations and an informal plenary dedicated to exploring possible adjustments to its work and working methods.

In a statement issued April 9, Adedeji Ebo, UN director and deputy to the High Representative for Disarmament Affairs, warned that “By failing to open a space for deliberations, we reinforce those claims that the United Nations is obsolete and unable to meet the challenges of the time.”

“The failure of the commission to complete its cycle, therefore, represents a tangible loss,” Ebo said.

In a separate statement the same day, the German delegation expressed regret over the meeting suspension. “We strongly regret that the Commission was not able to formally adopt the agenda of the substantive session and had to move into informal mode without discussing the working groups,” it said. “The commission therefore is not able to fulfill its mandate to have an exchange of thoughts and ideas with the goal to formulate recommendations—a task which is at the core of multilateralism.”

The Russia delegation also expressed regret, citing “the inability to conduct a comprehensive discussion including within the working groups, as well as to develop recommendations based on the results of the three-year cycle of the commission.”

During last year’s UNDC annual meeting, there were no apparent U.S. objections on including emerging technologies on the agenda. Julie Rodriguez, the emerging technologies working group chair, reported that the group held seven informal meetings, heard expert presentations on science and technology, and on their potential role and impact on international security and disarmament efforts, according to a UN press release. She also noted exchanges on “Member State-led initiatives related to emerging technologies.”

The failed UNDC consensus and process foreshadow a difficult path forward for international efforts on disarmament, especially ahead of the 2026 nuclear Nonproliferation Treaty Review Conference that began April 27. The Trump administration has often been critical of the UN and has decreased participation in its activities.

May 2026
By Daryl G. Kimball

For decades, a global ban on nuclear test explosions has been a central goal, and is now a central element, of the nuclear nonproliferation and disarmament regime because an effective, comprehensive, verifiable test ban directly constrains the ability of all parties to develop new or more-advanced nuclear weapons.

The push to end all nuclear test explosions has also been driven by the widespread human suffering and environmental contamination produced by more than 2,000 atmospheric and underground nuclear test explosions since 1945, the effects of which continue to affect downwind populations today.

Three decades after the conclusion of the 1996 Comprehensive Test Ban Treaty (CTBT), it has 187 signatures and near-universal support, but the treaty and the de facto global nuclear test moratorium are facing unprecedented new challenges. Not only have nine key states failed to ratify it, but there are new U.S. accusations of noncompliance against China and Russia, and President Donald Trump has threatened to resume U.S. nuclear testing for the first time since 1992.

The situation requires that all states parties urgently reaffirm the value of the CTBT and call for new measures to ensure compliance at this month’s nuclear Nonproliferation Treaty Review Conference and beyond.

Although the CTBT Organization’s International Monitoring System is more effective than originally envisioned, very low-yield nuclear test explosions can still be difficult to detect without short-notice, on-site inspections, which will only be available once the treaty enters into force.

This is why, some 20 years ago, civil society experts recommended that the “nuclear weapon states should implement confidence-building … measures at their sites” to ensure they are not currently engaged in prohibited activities. It is also why in 2023, the head of the U.S. National Nuclear Security Administration (NNSA), Jill Hruby, suggested that the United States, Russia, and China, could work together “to develop a regime that would allow reciprocal observation with radiation detection equipment at each other’s subcritical experiments to allow confirmation that the experiment was consistent with the CTBT.”

In the absence of the CTBT’s entry into force or new voluntary confidence-building measures, there remains risk that certain activities at these former nuclear testing sites that are prohibited—nuclear experiments that produce a self-sustaining nuclear chain reaction—might go undetected or might be misinterpreted as a nuclear explosive test.

This is the dangerous situation we are now facing.

Although U.S. nuclear weapons labs have confirmed year after year that there is no technical or military reason for renewed U.S. nuclear test explosions, on Oct. 30, 2025, Trump, threatened to resume nuclear testing “on an equal basis.” Since then, the White House and the NNSA have not been able or willing to clarify what kind of nuclear weapons tests Trump is talking about. In fact, the NNSA and U.S. Strategic Command have reaffirmed that there is no technical or military basis to restart nuclear explosive testing.

Nevertheless, an internal NNSA planning document from February indicates that the agency plans to “Execute the President’s directive with respect to the testing of the U.S. nuclear deterrent” before the end of 2028.

Trump’s impulsive directive to resume testing appears to be all about political retribution and his belief that some other nuclear-armed state has conducted a nuclear test in violation of a treaty that his administration does not support.

On February 6, a senior U.S. official alleged that China conducted a nuclear test explosion on June 22, 2020. U.S. officials also claim that data from a CTBTO primary seismic station in Kazakhstan shows that China conducted a 10-ton (TNT equivalent) nuclear test explosion. In 2019, Trump officials also claimed “Russia probably is not adhering to its nuclear testing moratorium in a manner consistent with the CTBT.”

However, the data available from the International Monitoring System and other seismic monitoring stations in the region do not indicate conclusively that the seismic events in China on June 22, 2020 were produced by a nuclear explosion, according to published statements from the CTBTO and respected nongovernmental scientific institutions. China and Russia have denied the U.S. allegations of nuclear testing.

Even if China conducted a clandestine nuclear test explosion in June 2020, or that Russia may have conducted such a test sometime after 1996, two nuclear wrongs don’t make a right.

Not only would further nuclear explosive testing by the United States (or others) violate the CTBT, but it would also undermine global security. Renewed U.S. explosive testing, at any yield, would set off a chain reaction of nuclear testing worldwide that would improve the nuclear capabilities of U.S. adversaries and blow apart the global nonproliferation system.

U.S. Assistant Secretary of State Christopher Yeaw stated Feb. 23 that he hoped the U.S. allegations would “spur a discussion on how we all approach responsible nuclear testing behavior going forward.” The only responsible nuclear testing behavior is not to do it and to take the steps necessary to detect and deter anyone else from doing so ever again.