Nuclear deterrence is a strategic concept aimed at preventing adversaries from taking hostile actions by demonstrating the credible threat of nuclear retaliation. 

As defined by the U.S. Department of War (previous named Department of Defense): “Deterrence is a strategy that seeks to prevent an actor from taking specific action and has been central to keeping peace for 70 years. Applying the enduring concepts of deterrence requires a continuous effort to tailor as the security environment evolves”[2]. This doctrine encompasses several critical components:

• A nuclear force included in U.S. arsenal such as intercontinental ballistic missiles (ICBMs) on land and at sea, strategic bombers, non-strategic nuclear forces or a robust command and control system (C2);
• A multi-layered missile defense that protects the U.S. and its allies from hostile ballistic missiles through neutralization, interception, and mitigation;
• Modernization because nuclear triad requires significant upgrades, including the enhancement of non-strategic systems;
• Tailored deterrence that shows that U.S. adapts to specific adversaries and evolving security threats rather than relying on a one-size-fits-all approach;
• And finally, arms control, particularly regarding Russia, China, North Korea and Iran.

The first nuclear bomb had occurred on July 16, 1945, in New Mexico, marking the culmination of the Manhattan Project, a top-secret initiative launched in 1942. Following the successful test, President Harry Truman authorized the use of nuclear weapons against Japan. On August 6, 1945, Hiroshima was bombed with « Little Boy, » and Nagasaki with « Fat Man » on August 9. Japan’s surrender on September 2 highlighted the unprecedented destructive power of nuclear weapons. Reflecting on this moment, Truman declared :

“… The atomic bomb. It is a harnessing of the basic power of the universe”[3].

This period also marked the origins of nuclear deterrence. President Truman’s signaling strategies soon evolved into key concepts such as first strike capability, secured second strike, and mutually assured destruction (MAD). Seeking to limit nuclear proliferation, Truman proposed the “Baruch Plan” in 1946, advocating for international control of nuclear weapons under the newly formed United Nations (UN). However, the Soviet Union, under Joseph Stalin, rejected the plan and conducted its first nuclear test in August 1949, just months after the creation of NATO. With two nuclear-armed superpowers now in direct opposition, the Cold War had begun. 13 years later, the Cuban Missile Crisis of October 1962 marked a defining moment in U.S. nuclear deterrence history.Over thirteen tense days, both Soviet Union and U.S.A. assessed the risks of a direct nuclear confrontation. This event fundamentally shaped U.S. nuclear deterrence doctrine.As a result, the Washington-Moscow “hotline” was established to facilitate direct communication and prevent future escalations.

However, the Cuban Missile Crisis also revealed the inherent paradox of nuclear deterrence—while it prevents war through fear of retaliation, it also increases the risk of unintended escalation. This paradox is evident in the ongoing war in Ukraine. On November 19, 2024, Vladimir Putin signed a decree formalizing Russia’s new nuclear doctrine in response to President Joe Biden’s authorization for Ukraine to use long-range missiles. Putin warned that any such action would be met with a nuclear response. On January 4, 2025, after intercepting eight U.S.-supplied ATACMS missiles fired by Ukraine at Russia, Moscow’s retaliation was not nuclear but rather an intensification of conventional attacks on Ukrainian infrastructure. Russia’s nuclear threats are more of a diplomatic and psychological tool rather than an immediate military strategy.

As Stephen Younger, physicist and author at the Woodrow Wilson International Center, stated: « Weapons developed through the course of history. And finally reached a stage with the nuclear weapon that for the first time ever, wars couldn’t be won »[4]. Following his words, if nuclear weapons have rendered wars unwinnable, why have the United States recently found it necessary to revise their nuclear deterrence strategy? Other all, we can ask ourselves: How can the modernization of U.S. nuclear deterrence effectively address emerging global threats while ensuring long-term strategic stability in an era of rising geopolitical tensions?

In this article, we will first explore the key institutions that underpin the United States’ nuclear deterrence strategy, examining the roles of the President, National Security Council, and military leadership (I. Article 1/2). Then, we will turn our attention to the modernization of the U.S. nuclear arsenal, starting with an overview of why modernization is necessary. We will then analyse the technological advancements within the nuclear triad, specifically focusing on its key components: ICBMs, submarines, and strategic bombers (II. Article 2/2). This clear separation will allow us to divide the article into two parts.

I. Key institutions of the U.S. nuclear deterrence

A. Figures and structures: the President of the U.S. (POTUS), NSC, and JCS

The President of United-States, as Commander-in-Chief of the Armed Forces, holds the ultimate authority over nuclear policy. He is also in charge of the Defense and Security Policy. The President clarifies the main point of the national policy and will determine everything indeed after that. Unlike foreign policy, defense and security policy concerns all domestic threats. The goal is to address the threat to the national security and providing the means to address these threats. As Camille Barbit and Emmanuelle Maitre explain in their text « Nuclear Issues in the 2020 U.S. Presidential Election », the President plays a central role as the guarantor of nuclear deterrence, with the objective of maintaining a force capable of preventing any nuclear aggression against the country or its allies[5].

The National Security Council (NSC) plays also a key role in formulating the United States’ nuclear deterrence policy, although it is not an executive body that directly manages nuclear forces or military strategy. The NSC is a high-level advisory body that provides guidance to the POTUS on national security matters, including nuclear deterrence. Overall, the NSC:

• Helps to define major directions for nuclear policy, including deterrence doctrines, response strategies in the event of a nuclear attack, and international relations regarding nuclear weapons;
• Coordinates recommendations on nuclear strategic choices, including the modernization of nuclear forces, the arsenal, and defense capabilities;
• In the event of a nuclear crisis, the NSC plays a crucial role in managing the situation and making decisions regarding potential responses.

“The Joint Chiefs of Staff (JCS) consist of the Chairman, the Vice Chairman, the Chief of Staff of the Army, the Chief of Naval Operations, the Chief of Staff of the Air Force, the Commandant of the Marine Corps, the Chief of the National Guard Bureau and the Chief of Space Operations”[7]. Even if the JCS is a crucial post in the US defense policy, it doesn’t have any direct command authority over nuclear forces. The Chairman of the JCS serves as the principal military adviser to the President, Secretary of Defense, and NSC, providing strategic guidance and recommendations on nuclear policy, force posture, and deterrence strategies.

B. DoW (ex-DoD) and USSTRATCOM

On the 6th of September 2025, President Trump has signed an executive order to rebrand the Department of Defense (DoD) as the Department of War (DoW) its pre-1947 name. The administration argues the change projects « strength and resolve » and shifts focus from defense to a more aggressive warfighting posture[10].The Department of Defense DoW (ex-DoD) is the main structure/department that deals with the nuclear deterrence strategy, ensuring national security and the protection of allies. First thing first, The DoW is actively engaged in upgrading weapons, delivery vehicles, and nuclear command-and-control infrastructure to maintain their effectiveness in a rapidly evolving threat landscape. This involves keeping nuclear forces flexible by allowing deployment across regions, using diverse flight paths, and offering multiple weapon options. Such flexibility allows for a rapid and adaptable response to shifting geopolitical dynamics. Then, the DoW implements measures to strengthen the nuclear command, control, and communications (NC3) systems to ensure that deterrence capabilities remain operational even in the event of an enemy first strike. Finally, to reinforce deterrence, the DoW ensures that nuclear capabilities are visible and strategically deployed, demonstrating strength and political resolve when necessary. This includes positioning nuclear forces in key locations and utilizing deterrence as a means of diplomatic leverage during crises.

The United States Strategic Command (USSTRATCOM) holds a key position in the nuclear deterrence of the United States. Its primary mission is to deter any strategic attack by maintaining a global combat force that is safe, secure, effective, and credible. If deterrence fails, USSTRATCOM is prepared to prevail in conflict. Written on their official website, “USSTRATCOM deters strategic attack through a safe, secure, effective, and credible, global combat capability and, when directed, is ready to prevail in conflict”[8]. Based at Offutt Air Force Base near Omaha, Nebraska, USSTRATCOM is one of the eleven unified commands of the DoW. It is responsible for several key areas, including strategic deterrence, nuclear operations, NC3, electromagnetic spectrum operations, global strikes, and missile threat assessments. USSTRATCOM integrates and coordinates the capabilities necessary to provide national leaders and combatant commanders with accurate and timely information. This enables them to understand global threats and respond swiftly to them.

In addition of the previous departments we saw, there are several other agencies involved in nuclear deterrence in the United States. These include the Office of the Assistant Secretary of Defense for Nuclear, Chemical, and Biological Programs (OASD-NCB), the Nuclear Weapons Council (NWC), the National Nuclear Security Administration (NNSA), the Defense Threat Reduction Agency (DTRA), and the Defense Intelligence Agency (DIA). These organizations collaborate closely to ensure the safety, security, and effectiveness of the U.S. nuclear deterrent, coordinating modernization efforts, intelligence, and response strategies to address emerging threats.

Having examined the key institutions that shape U.S. nuclear deterrence policy, it becomes clear that a coordinated approach involving the President, the NSC, the JCS, and various defense agencies is crucial in maintaining a credible nuclear force. However, to effectively counter emerging global threats, the modernization of U.S. nuclear capabilities is paramount. This transition leads us to explore the ongoing efforts in modernizing the U.S. nuclear arsenal, with a focus on updating the nuclear triad to ensure its continued relevance in an evolving security landscape.

[9].

As previously mentioned, we will address the modernization of the U.S. nuclear arsenal in the second part of the article, starting with an overview of why modernization is necessary.We will then analyse the technological advancements within the nuclear triad, specifically focusing on its key components: ICBMs, submarines, and strategic bombers (Part II of II). I therefore invite you to click on the next article (2/2).

II. Modernization of the US nuclear arsenal : the nuclear triad

A. Introductory remarks : the starting point of modernization

In the 21st century, the United States faces a rapidly evolving global security environment, marked by the resurgence of great power competition and the modernization of nuclear arsenals by adversaries such as Russia, China or Iran. At the heart of the U.S. nuclear strategy lies the nuclear triad, a three-pronged force structure designed to provide a robust and flexible deterrent. The triad consists of intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and strategic bombers[11]. Nevertheless, numerous components of the U.S. nuclear triad originated during the Cold War era and are now approaching the conclusion of their operational service life. For example, the Minuteman III ICBMs, first deployed in the 1970s, and the Ohio-class submarines, introduced in the 1980s, are aging and require replacement. Similarly, the B-52H bombers, which have been in service since the 1960s, are being upgraded to remain relevant in modern warfare.

The modernization of these systems is massive in scope and cost. The U.S. plans to spend up to $1.5 trillion over the next 30 years to overhaul its nuclear forces. This includes the development of new systems such as the LGM-35A Sentinel ICBM, the Columbia-class submarines, and the B-21 Raider stealth bomber, as well as the modernization of warheads and supporting infrastructure [Annex 1]. These investments are critical to addressing the growing capabilities of adversaries and ensuring that the U.S. nuclear triad remains a cornerstone of national security. As Richard C. Johnson, Deputy Assistant Secretary of Defense for Nuclear and Countering Weapons of Mass Destruction Policy, noted, “As the security environment evolves, adjustments to the 2022 Nuclear Posture Review may be required to sustain the ability to achieve nuclear deterrence, in light of enhanced nuclear capabilities of China and Russia and possible lack of nuclear arms control agreements”[12].

B. Technological modernization of the nuclear triad

The Minuteman III, first deployed in the 1970s, has undergone multiple life-extension programs to remain operational. However, the U.S. Air Force is now replacing it with the LGM-35A Sentinel, part of the Ground-Based Strategic Deterrent (GBSD) program. The Sentinel aims to enhance accuracy, survivability, and targeting flexibility, with an estimated cost of $141 billion. However, the program has faced delays and cost overruns, raising concerns about its timeline and budget. The Air Force plans to buy over 650 new missiles, with 400 set for deployment until the 2070s. The remaining missiles will be used for test flights and as spares. The Sentinel program has experienced substantial cost increases, with early estimates in 2016 projecting 85 billion for acquisition. By 2024, however, the acquisition cost had risen to 85 billion. By 2024, however, this cost increased to 141 billion. Additionally, the program has been delayed by several years, with the initial deployment now expected in the early 2030s [Annex 2].The Minuteman III carries W78 or W87 warheads. The NNSA is developing the W87-1, a modernized warhead that will be deployed on the Sentinel. The new warhead, costing $16 billion, will improve U.S. targeting of hardened enemy sites. The W87-1 will replace the W78 warhead, which has been in service since the 1970s. The W87-1 is designed with safety features and targeting capabilities intended to improve reliability and safety.  It will also feature a new fuze system, which dynamically adjusts detonation height based on missile accuracy, improving the ability to destroy hardened targets [Annex 2].

The U.S. Navy is replacing its aging Ohio-class submarines with the Columbia-class, which will carry the Trident II D5 SLBM [Annex 3]. The Columbia-class program, described as the nation’s top defense acquisition priority, is projected to cost 128 billion for development and procurement, with total life cycle costs reaching 128 billion for development and procurement, with total life cycle costs reaching267 billion. Delays in the program, however, could impact the U.S. ability to maintain a continuous at-sea deterrent. The Navy plans to build 12 Columbia-class submarines, with the first boat expected to begin its first deterrent patrol in 2031. However, delays in construction have pushed the delivery of the first submarine back by 12 to 16 months. The Columbia-class submarines will have a service life of 42 years and will be equipped with 16 missile tubes, each capable of carrying a Trident II D5 missile. The program is critical to maintaining the U.S. sea-based deterrent, as the Ohio-class submarines are nearing the end of their service lives.The Trident II D5 missile is undergoing a life-extension program to ensure its viability through 2084. The program includes upgrades to the missile’s guidance systems and warheads, such as the W76-2 low-yield warhead, which provides the U.S. with more flexible nuclear options. The total cost for the life-extension programs is estimated at $33.7 billion. The Trident II D5 has been successfully tested over 160 times since its introduction in 1990, and the life-extension program will ensure that the missile remains reliable and effective for decades to come. The program includes upgrades to the missile’s guidance systems, propulsion systems, and warheads. The W76-2 warhead, which has a yield of 8 kilotons, was first deployed in 2019 and provides the U.S. with a low-yield option for limited nuclear conflicts. The W88 warhead, which has a yield of 475 kilotons, is also undergoing a life-extension program to ensure its continued reliability.

The modernization of the U.S. nuclear arsenal is a critical response to the evolving global security environment, marked by the resurgence of great power competition and the rapid advancement of nuclear capabilities by adversaries such as Russia and China. The nuclear triad comprising ICBMs, SLBMs, and strategic bombers, remains the cornerstone of U.S. nuclear deterrence. However, many of these systems, developed during the Cold War, are nearing the end of their operational lives, necessitating a comprehensive modernization effort to ensure their continued effectiveness.

The U.S. is investing heavily in this modernization, with plans to spend up to $1.5 trillion over the next 30 years to overhaul its nuclear forces. Key programs include the development of the LGM-35A Sentinel ICBM, the Columbia-class submarines, and the B-21 Raider stealth bomber, as well as the modernization of warheads and supporting infrastructure. These efforts aim to address the growing capabilities of adversaries, maintain strategic stability, and ensure that the U.S. nuclear deterrent remains credible and flexible in the face of emerging threats. However, the modernization process is not without challenges. Programs such as the Sentinel ICBM and Columbia-class submarines have faced significant cost overruns and delays, raising concerns about their timelines and budgets. Additionally, the integration of new technologies and warheads adds complexity to the modernization effort. Despite these challenges, the modernization of the U.S. nuclear arsenal is essential to maintaining a credible deterrent and ensuring national security in an increasingly complex and dangerous world.

Overall, the modernization of the U.S. nuclear arsenal is a response to both the aging of existing systems and the evolving threats posed by adversaries. By upgrading the nuclear triad, the U.S. aims to ensure that its nuclear forces remain credible, flexible, and capable of deterring aggression in an increasingly complex and dangerous world. This effort is not only a matter of national security but also a critical component of global stability in the 21st century.

ANNEXS

Annex 1 : Arms Control Center. U.S. Nuclear Weapons Modernization : Costs & Constraints Fact Sheet. [Online] May 2023. Available at : https://armscontrolcenter.org/wp-content/uploads/2021/01/U.S.-Nuclear-Weapons-Modernization-Costs-Constraints-Fact-Sheet-v-May-2023.pdf 

Annex 2 : Arms Control Association. U.S. Nuclear Modernization Programs. 2024. Available at : https://www.armscontrol.org/factsheets/us-modernization-2024-update#submarines

Annex 3 : Columbia-Class. Columbia-Class Submarine Program. Available at : http://columbia-class.com/

Annex 4 : Missile Threat. Trident D5. 2024. Available at : https://missilethreat.csis.org/missile/trident/

SOURCES : 

[1] National Nuclear Security Administration (NNSA). On Deterrence, January 9 2018. [en ligne]. Disponible sur : https://www.youtube.com/watch?v=fHFm8-7bQSU.

[2] U.S. Department of Defense. (n.d.). 21st Century Nuclear Deterrence and Missile Defense. [online] Available at: https://dod.defense.gov/News/Special-Reports/21st-Century-Nuclear-Deterrence-and-Missile-Defense/.

[3] HarrySTrumanLibrary. VT2008-9-2 President Truman Announces Bombing of Hiroshima, Marc 22 2019. [online]. Available at: https://www.youtube.com/watch?v=n_A8LPtuX5c

[4] National Nuclear Security Administration (NNSA). On Deterrence, January 9 2018. [en ligne]. Disponible sur : https://www.youtube.com/watch?v=fHFm8-7bQSU.

[5] Barbit, C. and Maitre, E. (2020). Nuclear Issues in the 2020 U.S. Presidential Election. Fondation pour la Recherche Stratégique. Available at: https://www.frstrategie.org/sites/default/files/documents/programmes/observatoire-de-la-dissuasion/bulletins/2020/72.pdf

[6] U.S. Air Force. (2025). John D. Caine Biography. Available at: https://www.af.mil/About-Us/Biographies/Display/Article/2942633/john-d-caine/ + The New York Times. (2025). The New York Times Homepage. Available at: https://www.nytimes.com/

[7] Joint Chiefs of Staff. (2025). About the Joint Chiefs of Staff. Available at: https://www.jcs.mil/About/

[8] U.S. Strategic Command. (n.d.). Mission. Retrieved February 22, 2025, from https://www.stratcom.mil/About/Mission

[9] United States Department of Defense. Nuclear Matters Handbook 2020. [Online] Available at : https://www.acq.osd.mil/ncbdp/nm/NMHB2020rev/chapters/chapter1.html#:~:text=Nuclear%20deterrence%20is%20the%20bedrock,underwrites%20every%20U.S.%20military%20operation

[1O] DEBUSMANN JR, Bernd. Trump rebrands Department of Defense as Department of War. BBC News. [en ligne]. 20 september 2024. [consulté le 07 septembre 2025]. Disponible sur : https://www.bbc.com/news/articles/cgr9r4qr0ppo

[11] Arms Control Association. U.S. Nuclear Modernization Programs : 2024 Update. Available at: https://www.armscontrol.org/factsheets/us-modernization-2024-update#submarines

[12] U.S. Department of Defense. DoD Adjusts Nuclear Deterrence Strategy as Nuclear Peer Adversaries Escalate. 2024. Available at : https://www.defense.gov/News/News-Stories/Article/Article/3975117/dod-adjusts-nuclear-deterrence-strategy-as-nuclear-peer-adversaries-escalate/