Strategic Arms Limitation Talks II (SALT II) (1979) — Treaty Brief

Overview

The Strategic Arms Limitation Talks II (SALT II) treaty, negotiated between the United States and the Soviet Union in the 1970s and signed in 1979, aimed to curtail the arms race during the Cold War by limiting the number and types of strategic nuclear delivery systems each superpower could deploy. Building on the framework established by SALT I, SALT II sought to impose quantitative and qualitative restrictions on intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers equipped with nuclear weapons. Although the treaty was never formally ratified by the U.S. Senate due to geopolitical tensions, both parties initially pledged to abide by its terms, reflecting an important step toward arms control and strategic stability.

Key Obligations

• Limits on Strategic Offensive Arms: Both parties agreed to ceilings on the total number of strategic nuclear delivery vehicles, including ICBMs, SLBMs, and heavy bombers, with specific limits outlined in the treaty’s main text and Annex I.
• Restrictions on New Weapon Systems: The treaty prohibited the development and deployment of new types of strategic offensive arms that would significantly enhance the nuclear capabilities of either side (Article 6).
• Verification Measures: Both sides committed to data exchanges and on-site inspections to verify compliance, although the treaty’s verification regime was less intrusive than later arms control agreements.
• Submarine-Launched Ballistic Missile Limits: SALT II placed restrictions on the number and types of SLBMs and their launchers to prevent qualitative improvements in Soviet or American submarine nuclear forces.
• Heavy Bomber Restrictions: The treaty limited the number of heavy bombers equipped for nuclear armaments, including constraints on modifications that would increase their offensive capabilities.
• No Interference with Defensive Systems: SALT II explicitly did not restrict defensive systems such as anti-ballistic missile (ABM) systems, which were separately addressed under the 1972 ABM Treaty.

Signatories and Status

The primary signatories of SALT II were the United States and the Soviet Union, reflecting the bipolar nature of Cold War geopolitics and the focus on limiting strategic nuclear arsenals between these two superpowers. No other states were parties to the treaty, as the agreement was bilateral in scope. Despite the signing in 1979 by U.S. President Jimmy Carter and Soviet General Secretary Leonid Brezhnev, the U.S. Senate never ratified the treaty, largely due to the Soviet invasion of Afghanistan later that year and rising tensions between the two countries. Nonetheless, both sides initially pledged to adhere to the treaty's terms as a demonstration of good faith. The treaty effectively expired in 1986, and its provisions were succeeded by later arms control agreements such as the Intermediate-Range Nuclear Forces (INF) Treaty and the Strategic Arms Reduction Treaty (START) series.

Major Controversies

• Non-Ratification and De Facto Compliance: The U.S. Senate’s refusal to ratify SALT II created ambiguity about its legal status. Despite this, both superpowers largely observed the treaty’s limits until the mid-1980s, raising questions about the enforceability of arms control agreements that lack formal ratification.
• Verification Challenges: The treaty’s verification mechanisms were considered insufficient by some analysts, as they relied heavily on national technical means (e.g., satellite surveillance) and limited on-site inspections, which constrained transparency and increased mutual suspicion.
• Soviet Invasion of Afghanistan: The Soviet military intervention in Afghanistan in late 1979 severely damaged U.S.-Soviet relations, leading the United States to suspend its participation in SALT II and refuse ratification, which undermined the treaty’s political legitimacy.
• Interpretation Disputes: Both sides accused each other of violating the treaty’s provisions, particularly regarding the development of new missile systems and modernization programs. These disputes highlighted the difficulty of distinguishing between permissible upgrades and prohibited qualitative improvements.
• Withdrawal and Expiry: Although SALT II did not include explicit withdrawal clauses, the breakdown in cooperation and the emergence of new strategic challenges led to its practical obsolescence by the mid-1980s.

Recent Developments

In the past five years, SALT II itself has not been the subject of renewed negotiations or revival efforts, as it has been superseded by subsequent arms control treaties and frameworks. However, the legacy of SALT II continues to influence contemporary arms control discourse, particularly in discussions about verification regimes and the limits of bilateral agreements in a multipolar nuclear environment. The deterioration of U.S.-Russia arms control relations, including the expiration of the New START Treaty’s original term and the absence of a comprehensive replacement, has renewed interest in the principles and lessons of earlier agreements like SALT II, especially regarding the challenges of maintaining strategic stability without formal treaty structures.

Why It Matters Now

SALT II remains a foundational case study in the evolution of arms control diplomacy, illustrating both the potential and limitations of bilateral treaties in managing nuclear competition. Its history underscores the importance of political will, robust verification, and adaptability to geopolitical shifts—lessons that are critical today as the international community grapples with emerging nuclear challenges and the erosion of existing arms control frameworks. Understanding SALT II helps inform current efforts to negotiate new agreements that can effectively address the strategic realities of the 21st century.