U.S. Air Force Keeps Multiple-Warhead Option Open for Sentinel ICBM After Russia Treaty Ends.

The U.S. Air Force is advancing the LGM-35A Sentinel intercontinental ballistic missile into its critical engineering phase while deliberately leaving its future warhead loadout unresolved. With New START expired, that flexibility could significantly shape U.S. nuclear deterrence capacity and industrial production planning for decades.

The U.S. Air Force’s Sentinel intercontinental ballistic missile is entering its decisive engineering phase with a core capability variable still unresolved: how many nuclear warheads each missile will ultimately be configured to deliver, a decision that could materially expand or constrain America’s prompt-strike capacity from hardened silos. With the New START treaty now expired and no follow-on limits in place, the question is no longer academic. It sits at the intersection of weapon design choices, stockpile production realities, and deterrence strategy in a period of worsening great-power nuclear competition.
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With New START expired, the U.S. Air Force's LGM-35A Sentinel ICBM is advancing while its future warhead loadout remains deliberately undecided, preserving the option to stay single-warhead or shift toward multiple-warhead configurations as W87-1 and Mk21A modernization progresses and strategic deterrence requirements evolve (Picture source: L3Harris).

Recent reporting indicates Air Force officials declined to specify the Sentinel’s potential warhead loading when pressed, even as senior U.S. Strategic Command leadership publicly acknowledged that returning to a multiple-warhead ICBM posture would be a presidential-level policy lever. The significance is operational: a MIRVed ICBM force can generate more aimpoints per launcher and can surge deployed warheads without building more missiles, but it also changes crisis stability because each silo becomes a more valuable target. That tradeoff is why the United States and Russia spent decades moving toward single-warhead silo missiles under successive arms-control frameworks.

Sentinel is designed to give decision-makers options. The system is a new, three-stage solid-fuel missile, broadly analogous in mission profile to Minuteman III but engineered for decades of sustainment and digital upgradeability. Under its nose shroud sits a post-boost “payload bus” with a liquid-propulsion system used for precise orientation and reentry vehicle deployment, the same basic architecture required to dispense more than one warhead or to release penetration aids in tailored patterns. Northrop Grumman has briefed that this liquid-propulsion stage is central to improving placement accuracy, one of the few performance variables an ICBM program can credibly enhance without revealing classified metrics.

The current baseline remains a single warhead per missile. Congressional research has described Sentinel as initially deploying with W87-0 warheads now used on part of the Minuteman III force, before transitioning to the W87-1 warhead as it becomes available. Sentinel’s higher throw-weight could allow the Air Force, if directed, to deploy two or three warheads in a MIRV configuration or add countermeasures to defeat future missile defenses. The publicly stated plan remains one W87-1 per missile, but officials are not committing to how far that configuration could be “uploaded” now that treaty constraints have lapsed.

The warhead and reentry vehicle package is itself a major modernization program. The W87-1 is intended to be the first newly manufactured U.S. nuclear warhead in decades, incorporating enhanced safety, security, and producibility features while forcing the broader nuclear enterprise to reconstitute critical skills and supply chains. The National Nuclear Security Administration has completed the first fully qualified plutonium pit for the W87-1, a milestone because pit production capacity underpins any attempt to grow the deployed stockpile. The warhead will be carried in Lockheed Martin’s Mk21A reentry vehicle, an updated aeroshell derived from the Mk21 used with the W87 on Minuteman III. The Mk21A has completed an unarmed environmental flight test, validating reentry-relevant conditions and telemetry for a component that must survive extreme heating, vibration, and plasma effects while protecting the warhead’s arming and fuzing chain.

From an operational standpoint, Sentinel’s armament is about an assured, prompt strategic strike rather than tactical employment in the conventional sense. The land-based leg of the triad is designed for continuous alert, rapid execution once authorized, and broad target coverage within roughly 30 minutes of launch time, characteristics that complicate an adversary’s planning and raise the cost of coercion. The current Minuteman III loadout consists of 400 deployed missiles carrying one warhead each, either a W87 at roughly 300 kilotons or a W78 at roughly 335 kilotons, with technical “upload” potential on some missiles if policy shifts. Sentinel’s principal tactical contribution inside the strategic mission set is improved aimpoint confidence against hardened targets, better reliability and maintainability, and a payload architecture that can evolve as defenses and warning systems improve.

The program’s development history explains why the loadout debate is resurfacing now. Sentinel, formerly known as the Ground-Based Strategic Deterrent, was conceived because Minuteman III and its 1960s-era infrastructure have reached the point where further life extension risks compounding reliability and security problems, even as the United States modernizes nuclear command, control, and communications. The Air Force frames Sentinel as a megaproject that recapitalizes not only missiles but also 450 silos and more than 600 associated facilities across roughly 40,000 square miles, a scale comparable to multiple acquisition programs bundled into one. The infrastructure burden became the program’s Achilles’ heel in 2024, when cost growth triggered a critical Nunn-McCurdy breach and forced a restructuring that explicitly rebalanced plans toward new construction rather than refurbishing legacy silos.

Oversight bodies have warned that Sentinel’s restructuring window is also a chance to correct deeper deficiencies, including software maturation and an integrated schedule, because delays push added sustainment risk onto Minuteman III. The Air Force is targeting a late-decade pad launch as an early flight milestone and early-2030s initial operational capability, even as silo-based test timelines remain less defined in open reporting.

Strategically, the United States is pursuing Sentinel to preserve a credible triad in an environment where Russia fields modern systems, and China is expanding both the size and sophistication of its nuclear forces, while the post-Cold War arms-control framework continues to erode. In that context, keeping the Sentinel’s warhead loading as an open design and policy space provides leverage: the Air Force can maintain a single-warhead posture to support stability, but retain the technical pathway to upload warheads or add penetration aids if the threat environment or deterrence requirements change.

The near-term outlook is therefore less about whether Sentinel can carry multiple warheads and more about whether U.S. political leadership will want that option, and whether the stockpile and industrial base can support it at scale. As W87-1 production ramps and Mk21A integration advances, the missile’s payload bus architecture ensures the United States is not locked into a single answer. The fact that officials are now carefully avoiding a definitive public number is itself the signal: in a post-New START world, Sentinel is being built not just to replace Minuteman III, but to preserve strategic maneuver room for the decades ahead.