On 2 February, the US Department of Defense published its Nuclear Posture Review (NPR), setting forth the Trump administration's nuclear strategy. The new report's keynote, emphases, and China-related statements are rather different from those in the 2010 NPR and deserves much attention.
Compared with the 2010 report, this NPR differs significantly in the following four aspects.
First, it sharply increases the role of nuclear weapons in US security strategy. President Barack Obama put forward a nuclear-free-world initiative. The 2010 NPR report contained multiple statements on reducing the role of nuclear weapons in US security strategy. The Trump administration has fundamentally departed from this. Believing that America's dominant position in the land, sea, air, space, and cyber domains has been challenged, it gives more emphasis to the role of nuclear weapons in safeguarding the security of US and its allies and deterring nuclear or conventional wars. The new report announces an intention to develop 'modern, flexible and resilient nuclear capabilities' and enable them to play multiple roles.
Second, the primary objective of the US nuclear strategy will shift from dealing with nuclear terrorism and proliferation to 'deterring nuclear and non-nuclear attacks'. The 2010 NPR found that the threat of global nuclear war no longer existed and made the prevention of nuclear proliferation and nuclear terrorism one of its five critical objectives. The new report now regards 'deterring nuclear attack of any scale by a potential adversary' as the primary objective of American nuclear policy.
Third, the new NPR lowers the threshold of nuclear weapon use and argues for intensified development of low-yield nuclear weapons. The 2010 report promised to 'reduce the role of nuclear weapons in deterring non-nuclear attacks' and vowed to 'consider using nuclear weapons only in extreme circumstances' and 'not to use or threaten to use nuclear weapons against non-nuclear weapon states that have joined and abided by the Nuclear Non-Proliferation Treaty'. Two changes are quite prominent in the new report: it stresses the need to use nuclear weapons to 'deter non-nuclear attacks' and it weakens the previous negative security assurance commitment by declaring America's right 'to readjust the commitment', thus lowering the threshold of using nuclear weapons.
Fourth, for the first time in NPR history, the new report contains a specific strategy targeting China and identifies a need to prepare against conventional or nuclear attacks from China.
The new NPR is a mid-to-long-term plan for the maintenance, development and use of nuclear weapons. It is a weather vane for international security. Readjustment of America's nuclear strategy this time will also affect other countries' security decision-making and strain the China-US strategic balance.
As a result of these changes, first of all the position of nuclear weapons in international struggles will bottom out. During the Cold War, the US and Soviet Union started the nuclear disarmament process after a white-hot nuclear arms race and worked together to prevent proliferation of nuclear technology or materials. The world has since witnessed a gradual reduction of nuclear weapons, climaxing in the US' proposal for a nuclear-free world. The new NPR stresses the role of nuclear weapons in major power competition, nuclear deterrence, and security crises, and prioritizes nuclear weapon modernization. This may fundamentally reverse the decline in nuclear weapons, thus increasing the risk of a nuclear arms race.
A further consequence is a lower threshold for possession and use of nuclear weapons, thus challenging the rules of global nuclear arms control. In the new NRP report, the US proposes equipping its military with new low-yield nuclear weapons, developing intermediate-range nuclear missiles, and countering non-nuclear attacks with nuclear weapons. These propositions are heavy blows to the existing global nuclear framework. Development of low-yield nuclear weapons and a stress on their 'non-nuclear' nature may well provoke more countries to follow suit. Intermediate-range missiles may shake the very foundation of nuclear stability among major powers by allowing the US to deter its strategic adversaries at close range. The proposition to launch a nuclear counterattack 'in extreme circumstances', including lethal cyberattacks on American infrastructure and biological or chemical attacks on the American military, means a lower threshold for the use of nuclear weapons.
Additionally, this might destabilize the strategic relationship between China and the US. This stability is primarily based on the 'minimum security principle', i.e., China will still have sufficient second-strike capacity and is able to penetrate US missile defense and threaten big American cities even after suffering a nuclear attack. According to the new NPR, the US will enhance its 'saturation attack capability' by developing low-yield nuclear weapons, upgrading the nuclear triad, and developing submarine-launch cruise missiles. These measures will increase the probability of the US launch saturation attacks against China and destroy the latter's nuclear retaliatory capability, thus posing a major threat to China's survival. Meanwhile, the US has sped up deployment of missile defense systems, including deployment of THAAD in the ROK, enhanced defense of land-based missiles along its western coast and selling missile defense systems to Japan, leading to a greater strategic defense capability.
In the long term, these measures may well threaten the already relatively fragile nuclear strategic stability between China and the US. It is fair to say that this new nuclear strategy is rather aggressive and Cold War-like and very dangerous.
