NUCLEAR WEAPONSWhy the U.S. Nuclear Umbrella Underpins Non-Proliferation
Early in the Cold War, forward-deployed nuclear weapons were focused on deterrence and warfighting, compensating for the numerical superiority of communist armies. As Soviet capabilities improved and more countries became nuclear powers, the purpose of the U.S. nuclear umbrella expanded to include non-proliferation. In essence, the U.S. preferred to protect key allies like Japan rather than risk them developing their own arsenals.
On 27 September 1991, U.S. President George H.W. Bush addressed the nation to announce a milestone in nuclear disarmament, which included the full withdrawal of shorter-range nuclear weapons—so-called tactical, theatre or non-strategic weapons—from U.S. Navy vessels and foreign countries, albeit with some caveats in Europe.
Bush’s bold action rested on the assumption of an improving strategic environment, including reciprocal arms reductions by the Soviet Union, which were continued by Russia, Ukraine and other Soviet successor states for a while after 1991. It also assumed that the remaining U.S. nuclear forces would be sufficient to deter an attack on the U.S. or its allies, including Australia. Today, Chinese and Russian actions are undermining those assumptions, with dangerous implications.
Confronting the growing risk of nuclear war, Australia is rightly working with Japan and others to rejuvenate global momentum on non-proliferation and disarmament. This is vital work. But such efforts can only succeed if the international community recognizes the positive role that the U.S. nuclear umbrella—more formally called extended deterrence—continues to play in limiting the spread of nuclear weapons and calls out destabilizing conduct by China and Russia.
To appreciate the contribution to non-proliferation made by the U.S. nuclear umbrella, we need to understand its purpose and form.
Early in the Cold War, forward-deployed nuclear weapons were focused on deterrence and warfighting, compensating for the numerical superiority of communist armies. As Soviet capabilities improved and more countries became nuclear powers, the purpose of the U.S. nuclear umbrella expanded to include non-proliferation.
In essence, the U.S. preferred to protect key allies like Japan rather than risk them developing their own arsenals. U.S. and allied interests broadly aligned because all sides feared a multipolar arms race in which small, independent arsenals could be vulnerable to pre-emptive first strikes, while the custodial risks of accidental or unauthorized use were multiplied. Building independent nuclear capabilities would have also strained allies’ economic and financial resources. It would also have been unpalatable to the public in some countries, like Japan. The same logic applies now.
Australia is an interesting case in point. Having cooperated with Britain’s nuclear program, Australia engaged in a renewed debate about developing its own capability after China’s first nuclear test in 1964. In the end, the credibility of U.S. security guarantees helped inform Canberra’s decision to eschew pursuit of nuclear weapons and ratify the Nuclear Non-Proliferation Treaty in 1973.
