VINCE SCAPPATURA AND RICHARD TANTER
JANUARY 30 2026
I. INTRODUCTION
Vince Scappatura and Richard Tanter argue that the imminent expiration of the New START treaty on 6 February of this year marks not simply the end of a treaty, but the collapse of a wider decades-long framework constraining the nuclear arms race between the United States and Russia. The looming Congressionally-mandated reconversion to nuclear-capability of 30 aircraft in the U.S. Air Force’s B-52H bomber force de-nuclearised under the treaty illustrates how quickly those constraints can dissolve. The reconversions will increase USAF fleet of nuclear-capable B-52s from 46 to 76, raising the maximum potential loading requirement for long-range AGM-86B air-launched cruise missiles from 920 to 1,520. This will require no new platforms, minimal expenditure, and little technical effort, yet would substantially expand U.S. nuclear delivery capacity. Moreover, the B-52 renuclearisation pathway will place added strains on US alliance partners such as Australia where B-52 ‘rotational deployments’ are about to commence, and also on US reliance on nuclear-weapon free zone treaties’ permissiveness regarding ‘visits’ and ‘transits’ to provide effective nuclear basing access.
Vince Scappatura is Sessional Academic in the Macquarie School of Social Sciences at Macquarie University, and author of The US Lobby and Australian Defence Policy, Melbourne: Monash University Publishing, 2019.
Richard Tanter is Senior Research Associate at the Nautilus Institute, and Honorary Professor , School of Political and Social Science, University of Melbourne.
Disclaimer: The views expressed by the authors are solely their own and do not reflect the positions of any government or affiliated institution.
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Banner image: Lieuwe Hofstra, ‘61-0007’, from here, courtesy of Lieuwe Hofstra.
II. NAPSNET POLICY FORUM BY VINCE SCAPPATURA AND RICHARD TANTER
AFTER NEW START: THE B-52 STRATEGIC BOMBER AND THE COLLAPSE OF TREATY CONSTRAINTS
30 JANUARY 2026
From arms control to rapid rearmament
The New START treaty, the last remaining major bilateral arms control treaty between the United States and Russia, is due to expire on 5 February 2026. The prospects for either a last-minute extension or a functional replacement are now vanishingly small.
One particular danger arising from the treaty’s lapse concerns the U.S. Air Force’s B-52H Stratofortress bomber force. Under New START, 30 B-52s in the active fleet were converted from nuclear-capable aircraft to platforms equipped solely for conventional missions. If the treaty expires without replacement, these aircraft could be returned to nuclear capability in relatively short order.
Legislation signed by President Joe Biden on 23 December 2024 authorises the Secretary of the Air Force to reconvert conventionally modified B-52 bombers if New START is no longer in force.
When New START expires on 5 February 2026, authority to reconvert the B-52 force will rest with the Trump administration. If exercised, it would raise the number of nuclear-capable B-52s in the U.S. Air Force immediately available for operations from 46 to 76.
A nuclear capability held in reserve
Section 1626 of the FY2025 National Defence Authorisation Act (NDAA) gives authority to the Secretary of the Air Force to ‘reconvert the B-52 bombers that had been modified to carry only conventional weapons’ in order to conform to the New START Treaty. This authority remains in force at the time of writing.[1]
The original conversion of B-52 bombers to comply with New START began by September 2015 and was completed by Air Force Global Strike Command (AFGSC) no later than March 2017. In total, 41 B-52 aircraft were converted to conventional-only configuration. Of these, 30 are in the active fleet, while 10 are held in long-term storage at Davis-Monthan AFB; the remaining aircraft was lost in an aviation accident.
Should the Trump administration elect to exercise the authority provided under Section 1626, the statute requires that the process of making the B-52 available for nuclear certification commence ‘not later than 30 days after the expiration of the New Start Treaty’, with reconversions to be completed ‘by not later than December 31, 2029’.
The language employed by U.S. lawmakers does not specify if reconversion applies only to aircraft in the active fleet or also to those held in long-term storage. Nevertheless, the statutory timeline established by Congress envisages completion of any reconversion within a period of less than four years. In such a scenario, the number of nuclear-capable B-52s available to the U.S. Air Force would increase from 46 to 76, with the potential for an additional 10 aircraft to be restored and reactivated from storage.
Importantly, Section 1626 makes clear that reconversion does not occur automatically upon the expiration of New START. Rather, it grants discretionary authority to the Secretary of the Air Force, to be exercised only if directed by the administration in office.
Senior U.S. Air Force officials have reinforced this position while making clear that the service remains ready and able to implement it if directed. For example, General Thomas A. Bussiere, commander of AFGSG, stated during an Atlantic Council discussion on the U.S. strategic arsenal in June 2025, that, when the New START Treaty expires in February 2026,
‘there may be a direction to provide additional capacity, both on the land leg and the bomber leg. If directed, we are ready and prepared to execute [that order]. We have the capability and capacity to do it.’
Reversibility by design
There is no certainty about how difficult or costly reconversion of B-52 bombers to nuclear capability would be. However, available indications suggest that the process would be technically straightforward and relatively inexpensive.
Mark Gunzinger, a former B-52 pilot and Director of Future Concepts and Capability Assessments at the Mitchell Institute for Aerospace Studies, has argued that reconversion could be achieved without significant difficulty
‘It’s doable, and that’s the beauty of maintaining bombers that can be re-equipped with the appropriate [nuclear weapons] components.’
This assessment is echoed by Brian Knight, Deputy Senior Materiel Leader in the U.S. Air Force’s B-52 program office, who noted:
‘The work itself, I’m not going to get into the details other than to say, we know how to do it and it’s relatively easy.’
According to U.S. Air Force estimates, restoring nuclear weapon capability to approximately 30 B-52 bombers would cost around US$4.5 million; a negligible sum in the context of strategic force modernisation.
Incidentally, the apparent ease with which such reconversions can take place underscores a long-standing verification concern raised by the Russian Federation under New START, particularly with respect to bombers. Russian officials repeatedly argued that while compliance with bomber conversions could be verified procedurally, inspectors could not visually confirm that conversions were functionally irreversible.[2]
As Gunzinger himself noted, the conversion of part of the B-52 force was intended as ‘a hedge against future uncertainty’, a hedge made credible precisely because reconversion could be carried out quickly, easily, and at relatively low cost.
The political collapse of treaty restraint
President Donald Trump’s attitude to extension of this last remaining major bilateral arms control treaty has fluctuated. In July 2025, he appeared to understand and appreciate the potential consequences of the treaty lapsing, asserting: ‘When you take off nuclear restrictions, that’s a big problem.’
Then, in September 2025, Russian President Vladimir Putin offered to voluntarily maintain New START’s numerical limits on deployed strategic nuclear weapons for one year after the treaty’s expiration, provided the United States did the same. President Trump responded positively in October, stating that the proposal ‘sounded like a good idea’.
However, by January 2026, the U.S. president signalled a markedly different position. In an interview with the New York Times on 8 January, Trump indicated he would allow New START to expire without accepting Moscow’s proposal, stating: ‘If it expires, it expires. We’ll just do a better agreement.’
As of 15 January, Russia was still awaiting a formal response from the United States.
As a matter of law, the treaty cannot be formally extended beyond its expiry on 5 February, given its one-time five-year extension clause was exhausted when the treaty was extended in 2021. Nevertheless, under U.S. law, the executive branch may pursue a nonbinding or political commitment to continue observing New START’s central numerical limits, a step that would not necessarily require Senate action.
When treaty limits disappear
If New START expires without replacement, all legally binding caps on U.S. and Russian strategic nuclear forces will lapse. Putin’s proposal of a voluntary extension would apply only to the treaty’s numerical limits and would not restore its verification and transparency measures, which were already in a state of suspension following Covid-19 and, more significantly, in the context of the Russia-Ukraine war.[3]
The treaty’s demise therefore raises important questions about the future scale of nuclear deployments on U.S. strategic bombers, particularly the B-52.
Under New START, each heavy bomber is counted as a single nuclear warhead against the treaty’s deployed warhead limit, regardless of its actual payload. In operational terms, however, a B-52H can carry up to 20 long-range air-launched cruise missiles (ALCMs), each armed with a single W80-1 warhead.[4]
If maximum loading were adopted as the basis for wartime operations, the current force of 46 nuclear-capable B-52s could require up to 920 nuclear-armed cruise missiles. Should reconversion of the 30 active conventional-only B-52s be implemented (excluding those in storage), the number of nuclear-capable aircraft in the U.S. Air Force fleet would rise to 76, raising the maximum potential loading requirement to 1,520 nuclear-armed ALCMs.
By comparison, it is estimated that approximately 500 ALCMs are currently assigned to the U.S. bomber force, shared between the B-52 and B-2 fleets, with some deployed at bomber bases and the remainder held in central storage.
The collapse of the arms control framework
The impending expiration of New START marks not simply the end of a treaty, but the collapse of a wider decades-long framework constraining the nuclear arms race between the United States and Russia. The looming reconversion of the U.S. Air Force’s B-52H bomber force illustrates how quickly those constraints can unravel. It would require no new platforms, minimal expenditure, and little technical effort, yet would substantially expand U.S. nuclear delivery capacity.
The implications for strategic stability are significant. Even absent a decision by the Trump administration to reconvert the conventional B-52 force, once New START’s accounting rules and verification and transparency mechanisms disappear, the bomber leg’s latent warhead potential becomes far more consequential, introducing ambiguity into adversary threat perceptions and force planning.
Added strains on alliances and nuclear basing access
The B-52 renuclearisation pathway will place added strains on US alliance partners such as Australia where B-52 ‘rotational deployments’ are about to commence at Australia’s largest northern air base, and at the same as the roiling of Trump administration foreign policy has greatly increased domestic Australian concern about the AUKUS submarine project, the first phase of which see rotational deployment of US Navy Virginia-class attack submarines within a year.
The key condition for access of US nuclear-capable B-52 and B-2 bombers to Australian air bases are provisions in the Treaty of Rarotonga establishing the South Pacific Nuclear-Weapon Free Zone that on the one hand prohibit carefully defined ‘stationing’ of nuclear-armed vessels and aircraft, but on the other explicitly permit ‘transits’ and ‘visits’ – undefined in either duration or frequency – of nuclear-armed vessels and aircraft.[5] The authors discussed the history of these issues and their contemporary policy implications for both the Australian case and other US allied countries hosting nuclear-capable weapons platforms in two Nautilus Institute Special Reports: Nuclear-capable B-52H Stratofortress strategic bombers: a visual guide to identification, Nautilus Institute Special Report, 25 August 2024, and B-52 strategic bombers in Australia, 1979 – 1991 and the nuclear heterodoxy of Malcolm Fraser, Nautilus Institute Special Report, 4 August 2025.
To date these provisions have provided Australian governments with a degree of political protection to maintain that the presence of nuclear-capable US bombers in Australia do not void government claims to commitment to international law and arms control. The probable renuclearisation of at least 30 converted B-52s means that within four years all B-52s entering Australian territory will be nuclear-capable – further eroding the carapace of public acceptance of US nuclear weapon access to Australia.
In a different political and regional context, the renuclearisation process and the consequent jump in the numbers of nuclear-capable B-52s will exacerbate the growing difficulties of frequent presence of US nuclear-capable submarines and aircraft to the critical US naval and air base on Diego Garcia in the Indian Ocean. The island is part of the Chagos Archipelago, sovereignty over which is in the last stages of being transferred from the United Kingdom to Mauritius. Having previously acquiesced to this transfer, President Trump has reversed course, describing it as ‘an act of great stupidity’.
Mauritius is a signatory to the Treaty of Pelindaba establishing the African Nuclear Weapon Free Zone Treaty, which contains comparable prohibitions on stationing of nuclear weapons and permission for transits and visits of nuclear-armed vessels and aircraft as does the Treaty of Rarotonga. However, the African NWFZ Treaty has one important difference to the South Pacific treaty, insofar as it established the African Commission on Nuclear Energy, with authority for dispute resolution involving the treaty, including, through the Organisation of African Unity, taking unresolved matters of dispute to the United Nations Security Council.[6]
III. ENDNOTES
[1] The FY2026 NDAA was signed into law by President Trump on December 19, 2025. Although it made no reference to New START or the reconversion of the B‑52 conventional-only fleet, because section 1626 of the FY2025 NDAA did not include a sunset clause, and Congress has not enacted any legislation explicitly repealing or amending section 1626, that provision presumably remains in force at the time of writing.
[2] On 5 February 2018, the day New START treaty numerical limits entered into force, Russia formally notified the United States that one aspect of US compliance with the inspection protocols of the treaty had the result that Russia ‘cannot confirm that these strategic arms have been rendered incapable of employing SLBMs or nuclear armaments for heavy bombers’. This appeared to be a reference to the absence in the verification protocols for a capability to assess the functioning of certain electronic equipment in the bombers’ weapons bay. For a discussion of this complaint and its wider implications for arms control verification, see Vince Scappatura and Richard Tanter, Nuclear-capable B-52H Stratofortress bombers: a visual guide to identification, pp. 58-72.
[3] As noted above, Russia’s suspension of participation in the treaty in February 2023 followed almost five years of Russian dissatisfaction with the visual confirmation procedures of converted bombers.
[4] The W80-4 thermonuclear warhead, the modernised successor to the W80-1, is currently under development, with the first production unit expected in fiscal 2027. It will be integrated with the U.S. Air Force’s Long-Range Standoff (LRSO) cruise missile, to be carried by B-52 and future B-21 strategic bombers.
[5] See discussion of these issues by Vince Scappatura and Richard Tanter in their Nuclear-capable B-52H Stratofortress strategic bombers: a visual guide to identification, Nautilus Institute Special Report, 25 August 2024, and B-52 strategic bombers in Australia, 1979 – 1991 and the nuclear heterodoxy of Malcolm Fraser, Nautilus Institute Special Report, 4 August 2025.
[6] African Nuclear Weapon Free Zone Treaty (Treaty of Pelindaba), Article 12, and Annex IV, at https://treaties.unoda.org/t/pelindaba
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