The F-35A Joint Strike Fighter (JSF) armed with the B61-12 thermonuclear weapon is slated to be the cornerstone of NATO’s next-generation air-based nuclear deterrent, reigniting debate over the logic of US extended deterrence and deploying nuclear weapons in Europe.
This month, multiple media outlets reported that the F-35A JSF has officially been certified to carry the B61-12 thermonuclear bomb, marking a significant development in nuclear deterrence capabilities. This certification signifies the F-35A’s unique ability to penetrate enemy air defenses, making it NATO’s latest dual-capable aircraft for nuclear deterrence in Europe.
The F-35A’s stealth and advanced capabilities are expected to alter Russia’s defensive strategies and predictive modeling of strike success probabilities.
The aircraft’s certification, achieved in October 2023 ahead of the previously scheduled January 2024, underscores intense collaboration among 16 government and industry stakeholders over the past decade.
The F-35A is increasingly becoming Europe’s dominant 5th-generation stealth fighter. European Security & Defense notes in a July 2023 article that the UK, Italy, Netherlands, Denmark, Norway, Belgium, Finland, Poland and Germany have acquired or plan to acquire the aircraft.
Significantly, the F-35A does not require the Block 4 upgrade for B61-12 usage, alleviating concerns amid ongoing delays in the Block 4 and Technology Refresh-3 updates.
The certification process does not imply that all F-35As will actively participate in nuclear missions; only specific squadrons will have the qualifications and infrastructure to undertake such operations.
The deployment of the B61-12 in Europe remains a closely guarded secret, with Belgium, Germany, Italy and the Netherlands expected to continue hosting these weapons.
The B61-12’s capabilities, including a new guidance package, signify a substantial advancement over the older B61 gravity bomb.
The nuclear weapon’s guidance system gives it a circular error probable of 30 meters, combined with variable yield capability, allowing it to be used for tactical purposes on the battlefield and attack deeply buried targets such as command posts.
This certification also underscores the strategic importance of the F-35A amidst increasing tensions between NATO and Russia.
These spiking tensions could potentially impact NATO’s nuclear weapons-sharing program and its deterrent posture in Europe and beyond.
The move highlights the ongoing modernization of nuclear capabilities, reflecting the evolving security landscape and the critical role of stealth technology in nuclear deterrence.
Extended deterrence based on nuclear-sharing in Europe was a crucial part of US and NATO strategy throughout the Cold War, with Russia’s 2022 invasion of Ukraine reigniting debate about its relevance.
The 2022 US National Defense Strategy (NDS) emphasizes the importance of extended deterrence as a critical pillar of the US approach to maintaining strategic stability.
The document says extended deterrence involves leveraging the full spectrum of US military capabilities, including nuclear, conventional, and non-kinetic tools, in coordination with diplomatic efforts and alliances to deter adversaries and reassure allies.
The NDS underscores the vital role of allies and partnerships in amplifying US strategic efforts while advocating for increased cooperation, interoperability and burden-sharing to enhance collective defense and deterrence capabilities.
Nuclear sharing is a critical component of the US extended deterrence posture. In a November 2023 article for the Bulletin of Atomic Scientists, Hans Kristensen and other writers note that, contrary to common misconceptions, hosting nuclear weapons doesn’t grant non-nuclear states direct control over their launch or control.
They say that the governance of US nuclear weapons in Europe, facilitated through specific agreements with host nations, encompasses a wide array of collaborative activities ranging from storage and safety to delivery system provision.
They point out that US moves to modernize its nuclear infrastructure in Europe, alongside Russia’s aggressive posture and nuclear-capable deployments in Belarus, have put a new spotlight on nuclear-sharing arrangements.
As NATO integrates new members such as Sweden and Finland, the complexity and scope of nuclear sharing are expected to deepen in the years ahead.
Jonathan Masters and Will Merrow note in a March 2023 Council of Foreign Relations (CFR) article that while the scale of current US nuclear stockpiles in Europe remains classified, it is estimated that the US has 100 nuclear bombs stored there.
Masters and Merrow note that the US’s current nuclear arsenal in Europe consists entirely of B-61 gravity bombs, which have been in service since the 1960s.
In terms of the operational impact of nuclear-armed F-35As in Europe, Frank Kuhn mentions in a September 2023 War on the Rocks article that NATO’s nuclear deterrence strategy, based on the US B-61 gravity bombs, may be obsolete and no longer credible.
However, Kuhn notes that introducing the F-35A and modernized B61-12 nuclear bombs with enhanced precision-guidance capabilities marks a significant shift in the alliance’s capabilities against potential Russian aggression. He says that the F-35A offers NATO an unprecedented ability to penetrate sophisticated air defenses, thus improving the alliance’s nuclear deterrent.
He also says that the F-35A will facilitate increased cooperation among NATO members, allowing pilots from Eastern European countries to train in Western Europe for nuclear missions.
However, a modernized US extended deterrence posture in Europe based on F-35As armed with B61-12 nuclear bombs faces significant operational and strategic criticisms.
In a June 2023 article for The Defense Horizon Journal (TDHJ), Severin Pleyer mentions that criticism of the F-35A’s role in nuclear deterrence revolves around its generational classification, stealth capabilities and operational limitations.
Despite the F-35A’s marketing as a 5th-generation fighter, there’s a lack of clear, quantifiable metrics defining the category, especially regarding stealth, Pleyer notes. He says that advancements in radar technology by adversaries have cast new doubt on the longevity and efficacy of stealth as a singularly viable capability.
Pleyer also mentions operational concerns regarding the F-35A’s network-centric warfare approach, which emphasizes information sharing and battlefield awareness.
He says that while designed to enhance force interoperability, the aircraft’s limitations in payload capacity for nuclear munitions and dependence on external assets for mission success present substantial risks.
Moreover, Tytti Erästö, in a December 2023 article for the Stockholm International Peace Research Institute (SIPRI), argues that augmenting NATO’s already formidable conventional forces with an increased reliance on nuclear capabilities may not yield the intended deterrent effect.
Erästö points out this could escalate and exacerbate arms race dynamics rather than foster long-term security solutions. She also argues the rationale for deploying US tactical nuclear weapons in Europe may be outdated, as the conventional military balance now heavily favors NATO.
Despite that, Erästö says that the symbolic value of US nuclear weapons in Europe persists, underlining the transatlantic bond amid growing anxieties over Russian militarization and a possible spread of the Ukraine war into Europe.
Erästö also questions the idea of a limited nuclear war, pointing out the catastrophic humanitarian and environmental consequences of any nuclear weapon use.