This month, the US Congressional Research Service (CRS) released a report highlighting key issues surrounding the Sentinel Intercontinental Ballistic Missile (ICBM) program and broader concerns linked to the country’s land-based nuclear arsenal.
The Sentinel, officially known as the LGM-35A, is intended to replace aging Minuteman III missiles. However, critics have raised concerns about the high costs of developing and deploying the system, which is part of an estimated trillion-dollar overhaul of the US nuclear forces.
The CRS report mentions a heated debate over the strategic necessity of maintaining a land-based ICBM leg in America’s nuclear triad, the three-pronged military force structure comprised of ICBMs, submarine-launched ballistic missiles and strategic bombers. Some argue that new modern threats may have rendered stationary, silo-based systems vulnerable to preemptive strikes.
The CRS report says critics of the Sentinel program question whether such systems increase the risk of miscalculation or accidental launch, especially under crisis conditions, as they could pressure decision-makers into fatal rapid responses.
Proponents argue that the new missile will provide critical upgrades in reliability and security, ensuring an effective and credible deterrent against evolving global threats, as mentioned in the CRS report.
Despite escalating costs and fierce budget competition, the Sentinel program has emerged as a non-negotiable pillar in the US’s nuclear modernization strategy.
In July 2024, the US Department of Defense (DOD) confirmed the continuation of the Sentinel ICBM program despite an 81% cost overrun triggering a critical Nunn-McCurdy breach, which occurs when a defense acquisition program exceeds predetermined thresholds.
After a comprehensive review by the Office of the Secretary of Defense, led by William LaPlante, it was concluded that the Sentinel is crucial for national security with no viable alternatives.
The program’s acquisition cost now stands at US$140.9 billion, mainly due to increases in the command and launch segments. To address the cost issues, the DOD rescinded Milestone B approval and ordered a restructuring to ensure cost control and maintain nuclear deterrent capabilities.
However, the Sentinel program may continue at the expense of other US Air Force projects. For instance, Asia Times reported this month that the US Air Force faces significant budget constraints while advancing critical projects like the Next-Generation Air Dominance (NGAD) fighter, Next-Generation Aerial Refueling System (NGAS) tanker and Collaborative Combat Aircraft (CCA) drones.
Due to these financial challenges, Air Force Secretary Frank Kendall highlighted the need for “creativity” in force structure. Despite these programs’ interconnected operational and affordability aspects, modernization efforts are strained by commitments to nuclear deterrent upgrades and the growing threat from China.
Amidst intensifying debates on cost and relevance, the Sentinel ICBM is being scrutinized as both a cornerstone of deterrence and a potential trigger for escalatory risks.
In April 2024, Asia Times mentioned the debate surrounding the relevance of the US land-based nuclear arsenal. Proponents of maintaining a land-based nuclear arsenal argue that these weapons act as a “missile sponge” to absorb enemy strikes and provide a rapid first-strike capability.
Critics, however, highlight their vulnerabilities, such as the inability to survive a large-scale nuclear attack unless launched immediately and redundancy given the capabilities of bombers and nuclear ballistic missile submarines.
Further, Stephen Cimbala mentions in the 2023 book “Politics Between Nations” that proponents of replacing the aging Minuteman III missiles with the new Sentinel ICBM are essential for maintaining a credible deterrent within the nuclear triad.
In addition to providing first-strike capability, Cimbala says ICBMs complicate adversarial planning and add resilience to the US strategic force.
However, Cimbala says critics point out that ICBMs are first-strike vulnerable, and their fixed silos might escalate pressures toward a launch-on-warning posture.
He mentions critics propose downsizing or eliminating the ICBM leg, advocating for a dyad of sea-based missiles and bombers to reduce costs and avoid accidental escalation risks.
To keep the US ICBM force relevant, Cimbala suggests shifting to mobile or deep-underground basing for survivability, integrating antimissile defenses or even deploying conventional warheads on ICBMs for flexibility.
However, he points out that while modernization proponents see these upgrades as stabilizing, critics view them as fueling arms race dynamics amid emerging threats like cyber and space warfare, questioning if the ICBM force’s strategic value justifies its risks and financial costs.
As global powers ramp up their nuclear capabilities, the legacy of Cold War-era ICBMs is fueling a modern arms race shaped by shifting alliances and emerging threats.
During the Cold War, ICBMs were central to the nuclear arms race between the US and the Soviet Union, embodying mutually assured destruction (MAD). These missiles allowed each superpower to target the other’s cities and infrastructure thousands of kilometers away, reducing response time.
This situation created a balance of terror, deterring initial nuclear strikes due to fear of disastrous retaliation. The Strategic Arms Limitation Talks (SALT) in the 1970s aimed to limit ICBM arsenals.
Despite these efforts, ICBMs remained a dangerous element of Cold War strategy, symbolizing deterrence and the catastrophic risks of nuclear confrontation until 1991.
However, Asia Times mentioned this month that the recent ICBM tests of the US, Russia and China reflect each country’s efforts to modernize and enhance their nuclear capabilities amid rising global tensions.
Such tests underscore the shift from a bipolar to a triadic nuclear power structure, with China emerging as a significant player alongside the US and Russia.
This new arms race is marked by advancements in missile technology, the abandonment of arms control treaties and each nation’s strategic motivations to maintain or achieve nuclear deterrence.
There is also the potential for a new era of multi-front nuclear deterrence, with competitive alliances and expanding arsenals redefining global nuclear arms dynamics.