25 Pivotal Arms Control Treaties and Their Role in U.S. National Security
The history of arms control is, in many ways, the history of humanity trying to pull itself back from the brink. Since the dawn of the nuclear age, the United States has engaged in a complex, often contentious diplomatic effort to manage the world’s most dangerous weapons — not just through military power, but through negotiation, treaties, and international law. These agreements have shaped the strategic environment in which American national security decisions are made, sometimes preventing catastrophic conflicts, sometimes failing spectacularly, and always reflecting the geopolitical realities of their time.
Understanding these 25 pivotal arms control treaties and their role in U.S. national security means grasping something fundamental: arms control isn’t idealism. It’s strategic calculation. Every treaty on this list was signed because American policymakers concluded that constraining certain weapons — including their own — made the United States safer than an unconstrained arms competition would. That calculus hasn’t always been correct, and some agreements have collapsed under the weight of geopolitical shifts. But the architecture of international security that these treaties built has kept nuclear war from breaking out for eight decades.
From the Antarctic Treaty of 1959 to emerging discussions on regulating artificial intelligence in weapons systems, this list traces the full arc of U.S. arms control engagement — what was achieved, what was abandoned, and what still hangs in the balance.
The Strategic Imperative: Why Arms Control Matters for U.S. National Security
Before diving into the treaties themselves, it’s worth understanding why arms control is a national security tool, not merely a diplomatic nicety.
Deterrence and stability depend on predictability. When each side knows roughly what the other can deploy, the risk of miscalculation — launching a preemptive strike because you fear you’re falling behind — drops significantly. Treaties impose ceilings on arsenals, making the strategic environment legible.
Proliferation prevention is equally critical. Every additional country that acquires nuclear, biological, or chemical weapons represents a new vector of existential threat to the United States. A treaty that keeps even one nation from crossing that threshold is worth diplomatic capital.
Verification and transparency provide intelligence benefits that are often underappreciated. Arms control inspections and monitoring regimes give the U.S. legal access to facilities and data that would otherwise require covert collection. The inspection provisions of START treaties, for instance, delivered insights into Russian strategic forces that satellite imagery alone couldn’t provide.
Cost management matters too. Capping arms races prevents the ruinous expenditures that destabilize economies — a lesson the Soviet Union learned too late.
With that framework in place, here are the 25 treaties and agreements that have most profoundly shaped American national security.
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Early Efforts and the Cold War Era (1959–1990)
The Cold War produced the most urgent arms control imperative in history. Two superpowers armed with thousands of nuclear warheads needed mechanisms to prevent accidental war. The treaties of this era established the foundational architecture that still partially holds today.
Nuclear Arms Control
1. Antarctic Treaty (1959)
Signed by 12 nations and now boasting 56 parties, the Antarctic Treaty was the first post-World War II arms control agreement of significance. It prohibited military activities, weapons testing, and nuclear explosions on the continent, while also banning nuclear waste disposal there.
Its role in U.S. national security is foundational rather than immediate: it established the precedent that entire domains could be denuclearized through international agreement. That precedent directly informed subsequent treaties on outer space, the seabed, and the Moon.
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2. Limited Test Ban Treaty (LTBT, 1963)
Negotiated in the wake of alarming public health data on radioactive fallout from atmospheric nuclear tests, the LTBT prohibited nuclear weapons tests in the atmosphere, underwater, and in outer space — pushing testing underground.
For U.S. national security, this treaty served multiple functions simultaneously. It reduced the radioactive contamination affecting American civilians, slowed the pace of Soviet nuclear development by removing the most observable test environment, and — critically — helped de-escalate Cold War tensions following the Cuban Missile Crisis of 1962. Over 100 nations signed it.
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3. Outer Space Treaty (1967)
Space was emerging as a potential theater of conflict, and the Outer Space Treaty preemptively closed that door. It prohibits placing nuclear weapons or other WMDs in orbit, on the Moon, or on other celestial bodies, and bans military installations on the Moon.
The treaty preserved U.S. space assets — satellites for surveillance, communication, and navigation — from becoming legitimate military targets in a legally recognized arms domain. Given that GPS, reconnaissance satellites, and missile early-warning systems underpin virtually every aspect of modern U.S. military power, protecting the peaceful-use norm in space has been enormously valuable.
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4. Treaty on the Non-Proliferation of Nuclear Weapons (NPT, 1968)
If there is one treaty that has done more to preserve U.S. national security than any other on this list, it is the NPT. Entering into force in 1970 and now with 191 states parties, it remains the cornerstone of the global non-proliferation regime.
The NPT divides the world into nuclear-weapon states (the U.S., Russia, UK, France, and China) and non-nuclear-weapon states, committing the latter to forgo nuclear weapons in exchange for access to peaceful nuclear technology and a vague commitment from nuclear states to eventually disarm. India, Israel, Pakistan, and South Sudan never joined; North Korea withdrew in 2003.
The NPT’s role in U.S. national security is difficult to overstate. Without it, analysts estimate the world might have 30 or more nuclear-armed states today. Each proliferation event multiplies the risk of nuclear use — whether deliberate, accidental, or by a non-state actor obtaining material.
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5. Seabed Arms Control Treaty (1971)
This treaty prohibits the placement of nuclear weapons and other WMDs on the ocean floor beyond a 12-nautical-mile coastal zone. It closed a potential arms race before it could begin — preventing the establishment of nuclear weapons platforms on the seabed that would have been nearly impossible to monitor or verify.
For U.S. naval strategy, which depends heavily on freedom of the seas and submarine-based deterrence, keeping the ocean floor free of fixed nuclear installations maintained a strategic environment favorable to American power projection.
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6. Anti-Ballistic Missile Treaty (ABM Treaty, 1972)
The ABM Treaty was one of the most intellectually sophisticated arms control agreements ever negotiated. Its premise — that limiting defensive systems stabilizes deterrence — runs counter to intuition but is logically sound: if one side builds an impenetrable missile defense, it can launch a first strike without fear of retaliation, destabilizing mutual deterrence.
The treaty restricted each party to two ABM deployment sites (later reduced to one) and prohibited nationwide missile defense systems. It kept the nuclear balance stable for three decades. President George W. Bush withdrew the U.S. from the treaty in December 2001, effective June 2002, to pursue a national missile defense system against rogue states like North Korea and Iran. The withdrawal fundamentally altered the strategic relationship with Russia.
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7. Strategic Arms Limitation Treaty I (SALT I, 1972)
SALT I, negotiated by the Nixon administration and Soviet Premier Brezhnev, imposed a five-year freeze on the number of strategic ballistic missile launchers. It capped ICBMs and submarine-launched ballistic missiles (SLBMs) at existing levels, preventing runaway quantitative growth in the most destructive nuclear delivery systems.
This was the first agreement to actually limit strategic offensive nuclear weapons, not merely regulate testing environments. It gave both superpowers breathing room and established the template — direct bilateral negotiation with quantitative limits and verification — that would define arms control for decades.
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8. Strategic Arms Limitation Treaty II (SALT II, 1979)
SALT II went further than its predecessor, setting an overall limit of 2,400 strategic nuclear delivery vehicles and sublimits on MIRVed systems (missiles carrying multiple independently targetable warheads). President Carter signed it, but the Soviet invasion of Afghanistan led him to withdraw the treaty from Senate consideration.
Though never ratified, both the U.S. and USSR largely observed SALT II’s limits for years — a testament to how arms control norms can provide stability even without formal legal force. The treaty represents an underappreciated case study in informal arms restraint.
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9. Intermediate-Range Nuclear Forces Treaty (INF Treaty, 1987)
The INF Treaty was a landmark achievement: the first agreement to actually eliminate an entire class of nuclear weapons rather than merely limit them. It required the U.S. and USSR to destroy all ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers — ultimately eliminating 2,692 missiles.
For European security and U.S. NATO commitments, the INF Treaty was transformative. Soviet SS-20 missiles had held European cities hostage with minimal warning time; their elimination dramatically reduced the threat to American allies. The Trump administration withdrew from the INF in August 2019, citing Russian development of the noncompliant 9M729 cruise missile — a development that has since reignited concerns about a new European missile threat environment.
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Biological and Chemical Weapons Control
10. Biological Weapons Convention (BWC, 1972)
The BWC entered into force in 1975 and now has 185 states parties. It was the first multilateral disarmament treaty banning an entire category of weapons, prohibiting the development, production, stockpiling, and transfer of biological agents for hostile purposes.
The BWC’s weakness has always been verification — unlike the Chemical Weapons Convention, it has no formal inspection mechanism. But its normative power is significant: it established biological weapons as categorically unacceptable under international law, creating political and reputational costs for any state pursuing such programs, which serves U.S. interests by stigmatizing a class of weapons that American forces would struggle to defend against at scale.
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Conventional Arms Control
11. Conventional Armed Forces in Europe Treaty (CFE Treaty, 1990)
Negotiated as the Cold War was ending, the CFE Treaty imposed limits on five categories of conventional military equipment — tanks, artillery, armored combat vehicles, combat aircraft, and attack helicopters — across the Atlantic-to-the-Urals zone.
At its peak, the CFE regime mandated the destruction of over 70,000 pieces of military equipment. For U.S. national security in Europe, it reduced the massive conventional force advantage the Warsaw Pact had held over NATO, fundamentally changing the threat calculus. Russia suspended participation in 2007; the West subsequently suspended implementation; Russia formally withdrew in 2023 — marking the effective collapse of conventional arms control in Europe.
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Post-Cold War and Modern Arms Control (1991–Present)
The end of the Cold War didn’t end the arms control imperative — it transformed it. New challenges emerged: managing the inheritance of Soviet nuclear weapons, preventing proliferation in unstable states, and controlling weapons that move through global trade networks rather than national arsenals.
Strategic Nuclear Arms Reduction
12. Strategic Arms Reduction Treaty I (START I, 1991)
START I was a genuine watershed. Unlike SALT, which froze arsenals in place, START I reduced them — requiring both the U.S. and USSR (succeeded by Russia) to cut to 6,000 accountable warheads and 1,600 delivery vehicles. It included an intrusive verification regime with on-site inspections, data exchanges, and continuous monitoring.
The treaty’s implementation became complicated by the Soviet collapse, eventually requiring Ukraine, Kazakhstan, and Belarus to transfer their inherited nuclear weapons to Russia — a non-proliferation achievement of enormous consequence for U.S. security. START I expired in December 2009.
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13. START II (1993)
START II aimed to cut each side’s deployed strategic warheads to between 3,000 and 3,500 and — critically — eliminate MIRVed ICBMs, the most destabilizing weapons in the nuclear inventory (a single missile carrying multiple warheads creates enormous incentive for first strikes). Russia ratified it conditionally; the U.S. ratified in 1996. But Russia formally withdrew in 2002 after the U.S. withdrew from the ABM Treaty, and START II never entered into force.
It stands as a cautionary tale about how arms control agreements are interconnected: withdrawal from one treaty can unravel others.
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14. Strategic Offensive Reductions Treaty (SORT / Moscow Treaty, 2002)
Negotiated in just one day of formal talks between Presidents Bush and Putin, SORT set limits of 1,700–2,200 operationally deployed strategic warheads by December 31, 2012. Critics noted its significant weaknesses: no verification mechanism, no limits on reserve warheads, and its limits happened to expire on the same day the treaty itself expired.
Nevertheless, SORT reflected the post-Cold War cooperative impulse and maintained the bilateral dialogue on nuclear weapons that has been continuous, if turbulent, since SALT I.
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15. New Strategic Arms Reduction Treaty (New START, 2010)
New START became the last functioning bilateral nuclear arms control agreement between the United States and Russia. It limits each side to 1,550 deployed strategic nuclear warheads, 700 deployed ICBMs, SLBMs, and heavy bombers, and 800 deployed and non-deployed launchers. It includes robust verification measures: 18 annual on-site inspections, continuous data exchanges, and telemetry sharing.
The Biden administration extended New START for five years in February 2021. Russia suspended its participation in February 2023, citing U.S. support for Ukraine, though it stated it would continue observing the warhead limits. The treaty’s expiration in 2026 without a successor agreement would leave the U.S. and Russia with no mutual nuclear constraints for the first time since 1972 — a genuinely alarming prospect.
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Comprehensive Nuclear Testing and Proliferation Control
16. Comprehensive Nuclear-Test-Ban Treaty (CTBT, 1996)
The CTBT prohibits all nuclear weapons test explosions and has been signed by 187 states and ratified by 178. But it cannot enter into force until eight specific states ratify it — including the United States, China, Egypt, India, Iran, Israel, North Korea, and Pakistan. The U.S. signed in 1996 but the Senate rejected ratification in 1999.
Despite not being legally binding for the U.S., it has observed a testing moratorium since 1992. The CTBT’s International Monitoring System — a global network of seismic, hydroacoustic, infrasound, and radionuclide sensors — provides the U.S. intelligence community with extraordinary detection capabilities, effectively making it a U.S. national security asset regardless of ratification status.
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17. Missile Technology Control Regime (MTCR, 1987)
Technically not a treaty but an informal political arrangement among 35 member states, the MTCR restricts exports of missiles, rockets, and related technology capable of delivering WMDs — specifically systems capable of carrying a 500-kilogram payload at least 300 kilometers.
For U.S. national security, the MTCR has been an important tool for slowing proliferation of ballistic missile technology to states like Iran, North Korea, and Pakistan. It relies on voluntary compliance, which creates enforcement challenges, but it has materially slowed the pace at which potentially hostile states have been able to develop long-range delivery systems.
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Chemical Weapons Disarmament
18. Chemical Weapons Convention (CWC, 1993)
The CWC, which entered into force in 1997, represents the most successful disarmament effort in history. With 193 states parties, it prohibits the development, production, stockpiling, use, and transfer of chemical weapons and established the Organisation for the Prohibition of Chemical Weapons (OPCW) as a verification body.
In July 2023, the United States completed the destruction of its entire declared chemical weapons stockpile — a process that took decades and involved the dismantlement of facilities storing mustard gas, nerve agents, and other agents accumulated during the Cold War. The CWC’s verification regime has also been invoked to investigate alleged chemical weapons use in Syria and the Salisbury nerve agent attack in the UK, demonstrating its ongoing operational relevance.
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Transparency and Confidence-Building Measures
19. Open Skies Treaty (1992)
The Open Skies Treaty established a program of unarmed aerial observation flights over the entire territory of member states, allowing any party to conduct surveillance overflights of any other party using specified sensors. Entered into force in 2002, it had 35 member states.
The U.S. withdrew in November 2020, citing Russian non-compliance in restricting flights over certain areas. Russia withdrew the following year. During its active years, Open Skies provided the U.S. military and intelligence community with legal overflight access to Russian territory and gave European allies confidence-building imagery they couldn’t obtain independently — a loss that most U.S. allies considered more costly than the administration acknowledged.
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20. Vienna Document (1990, repeatedly updated)
The Vienna Document is an OSCE (Organization for Security and Cooperation in Europe) agreement on confidence and security-building measures that requires member states to exchange information on military forces, provide notifications of military exercises, and accept inspection visits.
While less prominent than formal treaties, the Vienna Document has served as a foundation for military transparency across Europe, reducing the risk of misinterpretation of normal military activities as preparations for attack — a concern that’s particularly acute during periods of heightened tension like the current conflict in Ukraine.
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Conventional Arms Trade and Small Arms
21. Wassenaar Arrangement (1996)
Established as a successor to the Cold War-era COCOM export control regime, the Wassenaar Arrangement coordinates export controls among 42 member states on conventional arms and dual-use goods and technologies — items with both civilian and military applications.
For U.S. national security, the Wassenaar Arrangement helps prevent adversaries from acquiring advanced military technology through commercial channels. It’s particularly relevant for controlling exports of items like night-vision equipment, precision machine tools, and advanced semiconductors that could enhance the military capabilities of potential adversaries.
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22. Arms Trade Treaty (ATT, 2013)
The ATT establishes global standards regulating the international trade in conventional arms, from small arms to battle tanks and combat aircraft. It requires states to assess whether arms exports risk being used in human rights violations or fueling conflict. The U.S. signed the treaty in 2013 but did not ratify it. In 2019, the Trump administration formally unsigned it; the Biden administration subsequently notified the Senate of its intent to pursue ratification, though this was not completed.
The treaty’s relevance to U.S. national security lies primarily in reducing the flow of weapons to destabilizing actors — illicit arms that often eventually threaten American forces or interests.
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Non-Proliferation Enforcement
23. Proliferation Security Initiative (PSI, 2003)
The PSI is not a treaty but an international framework launched by the George W. Bush administration in the aftermath of revelations about the A.Q. Khan nuclear proliferation network. Now with over 100 participating states, it establishes principles and operational mechanisms for interdicting shipments of WMD-related materials at sea, in the air, and on land.
PSI has facilitated dozens of interdictions of proliferation-related cargo. Its most notable success was contributing to the interdiction of the German-flagged vessel BBC China in 2003, which was carrying centrifuge components destined for Libya’s nuclear program — an interdiction that helped precipitate Libya’s decision to abandon its WMD programs entirely.
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Emerging Domains
24. Fissile Material Cut-off Treaty (FMCT – Proposed)
The FMCT would prohibit the production of fissile material — highly enriched uranium and plutonium — for nuclear weapons purposes. It has been under negotiation at the Conference on Disarmament in Geneva for decades without success, primarily due to Pakistani objections.
Though not yet a treaty, U.S. advocacy for an FMCT reflects a core national security interest: the amount of fissile material in the world directly determines the upper bound of the nuclear weapons that can exist. Stopping production is, in theory, the most direct way to cap global nuclear arsenals.
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25. Emerging Norms on Cyber Operations, AI, and Autonomous Weapons
The final entry on this list is a category rather than a single agreement — and that reality itself says something important about where arms control is heading. There are currently no binding international agreements governing offensive cyber operations, the use of artificial intelligence in weapons targeting, or fully autonomous lethal weapons systems. But the discussions are intensifying.
The United Nations Group of Governmental Experts on Lethal Autonomous Weapons Systems (LAWS) has been meeting since 2014. The U.S. has issued its own policy on autonomous weapons that requires “appropriate levels of human judgment” over the use of lethal force. Bilateral discussions with China and Russia on cyber “rules of the road” have occurred but produced no binding commitments.
For future U.S. national security, these emerging domains may prove more consequential than any traditional arms control challenge. An AI-enabled, autonomous weapons competition with China could move at speeds and scales that render human decision-making irrelevant — a destabilizing prospect that makes treaty-making in this space an urgent priority.
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The Evolving Landscape: Challenges and the Future of Arms Control
The arms control architecture built over the past seven decades is under more strain today than at any point since the early Cold War. Several converging pressures are reshaping the environment.
Treaty withdrawals have accelerated. The U.S. has exited the ABM Treaty (2002), the INF Treaty (2019), and Open Skies (2020). Russia has suspended New START participation (2023) and withdrawn from the CFE Treaty (2023). Each withdrawal removes a layer of mutual constraint and predictability.
New military technologies — hypersonic glide vehicles, autonomous weapons, directed-energy weapons, and AI-enabled targeting — are outpacing existing treaty frameworks designed around ICBMs and bombers. No current agreement addresses hypersonic weapons, which travel at speeds exceeding Mach 5 and can maneuver to evade traditional missile defenses.
The multipolar nuclear environment is perhaps the most structurally challenging shift. Cold War arms control was fundamentally bilateral — U.S. and USSR. Today, China is rapidly expanding its nuclear arsenal (estimated to reach 1,000 warheads by 2030 according to the U.S. Department of Defense), while North Korea has conducted six nuclear tests and continues advancing its ICBM program. Neither country participates in any bilateral arms control framework with the United States.
Verification challenges have grown more complex. Some Russian treaty violations — like the INF-busting 9M729 missile — demonstrate that verification mechanisms designed for a cooperative relationship don’t automatically prevent cheating in an adversarial one.
The future of arms control may require fundamentally different approaches: multilateral rather than bilateral frameworks, technology-specific agreements rather than weapons-class limits, and confidence-building measures that work even in competitive strategic environments rather than cooperative ones.
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Frequently Asked Questions
What is the most important arms control treaty for U.S. national security?
The Non-Proliferation Treaty (NPT) is arguably the most consequential. By limiting nuclear weapons to five recognized states, it has prevented the proliferation of nuclear weapons to dozens of additional countries, each of which would represent a new existential threat vector for the United States.
What happened to New START after Russia suspended participation?
Russia announced its suspension of New START in February 2023, citing U.S. military support for Ukraine. Russia stated it would continue observing the warhead limits but halted inspections and data exchanges. The treaty expires in February 2026, and no successor negotiations are currently underway, potentially leaving the U.S. and Russia without mutual nuclear constraints for the first time since 1972.
Why did the U.S. withdraw from the INF Treaty?
The Trump administration withdrew from the INF Treaty in August 2019, citing Russian deployment of the 9M729 (SSC-8) cruise missile, which the U.S. assessed violated the treaty’s prohibition on ground-launched cruise missiles with ranges between 500 and 5,500 kilometers. Russia denied the violation. Following the withdrawal, the U.S. tested ground-launched cruise and ballistic missiles that would have been prohibited under the treaty.
Is the U.S. legally bound by the CTBT even though it hasn’t ratified it?
No. The U.S. signed the CTBT in 1996, which creates an obligation not to take actions that would defeat the treaty’s “object and purpose” under international law. But the Senate rejected ratification in 1999, so the CTBT is not legally binding on the U.S. The U.S. has maintained a testing moratorium since 1992, but this is a voluntary political commitment, not a legal obligation.
How does arms control differ from disarmament?
Arms control regulates, limits, or manages weapons and military activities without necessarily eliminating them — it’s about managing the threat to stable, predictable levels. Disarmament aims at complete elimination of specific weapons or weapon categories. Most of the treaties on this list are arms control agreements; the Chemical Weapons Convention is one of the few that actually mandates disarmament — the complete elimination of declared stockpiles.
Why doesn’t the U.S. have an arms control agreement with China?
China has historically refused bilateral nuclear arms control negotiations, arguing that its arsenal is too small relative to U.S. and Russian forces to warrant equivalent constraints. As China’s nuclear arsenal grows — potentially tripling in size by 2035 — this logic becomes increasingly difficult to sustain, and U.S. policymakers have made including China in future arms control frameworks a stated priority.
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Conclusion
The 25 pivotal arms control treaties and agreements detailed here tell a coherent story: the United States has repeatedly concluded that managing weapons through negotiation serves its national security interests better than unconstrained competition. Sometimes those conclusions were correct and the agreements delivered decades of stability. Sometimes they failed, were violated, or collapsed under geopolitical pressure. The INF Treaty’s elimination of an entire missile class was a genuine triumph; its eventual collapse revealed the fragility of arms control in a deteriorating strategic relationship.
What’s clear is that the loss of these frameworks is not cost-free. Each treaty that expires without a successor removes a layer of transparency, predictability, and mutual constraint that reduces the risk of catastrophic miscalculation. As the world moves into a multipolar nuclear era with new technologies, new actors, and deteriorating great-power relations, the case for arms control hasn’t weakened — it’s become more urgent. The challenge is building agreements that work in a world that looks nothing like the bipolar Cold War environment in which most of these frameworks were designed.
The architecture of international security is always under construction. These 25 agreements are its most important blueprints.