National security can be conceptualized in different ways—in the US, policymakers typically adhere to a traditional, Western national security paradigm, focusing on external threats to the state, such as attacks by outside actors.  Nuclear weapons have played a prominent role in US security policy since the first atomic bomb was dropped more than 75 years ago.  While different administrations have placed greater or less emphasis on nuclear weapons, deterrence has always played a key role.  The US uses nuclear weapons to discourage adversaries from both nuclear and conventional attacks by threatening costly retaliation.  Policymakers place a high value on the role of nuclear weapons in deterring attacks, but this comes with significant risk.

 

Deterrence theory is based on assumptions about how the international order works.

 

The concept of deterrence assumes actors will behave rationally, calculating the strategic benefits and costs of potential action.  This is a dangerous assumption, and doesn’t consider ideology, mental illness, or any number of emotional and psychological factors that influence decision-making.  It also assumes perfect information, which is unrealistic.  How one country perceives the actions of another, regardless of whether that perception is accurate, plays a significant role in decision-making.  It is virtually impossible to definitively known the intentions of other states, potentially leading to grave consequences.  

 

Deterrence also fails to account for technical malfunction, human failure, false warnings, or unauthorized action.  The US keeps its nuclear missiles on high alert to protect its second-strike capability.  Leaders have approximately 15 minutes to determine if there is an incoming attack.  There have been countless near misses throughout history.  For example, in 1995, a Norwegian rocket carrying scientific equipment was picked up on Russian radar.  The rocket resembled a US submarine launched nuclear missile, leading Russian radar crew to report the possibility of an incoming missile.  Russian president Boris Yeltsin went so far as to activate the nuclear football to prepare for a retaliatory attack.  Fortunately, the incident did not result in a nuclear exchange.  

 

Nuclear weapons are not that useful for deterring many of the international threats faced today, such as cyberattacks and terrorism.  Technological advancements in artificial intelligence may also negatively affect credible deterrence in the future.

 

Technological advancements reduce the ability of nuclear weapons to deter attack.

 

Technological advancements to conventional weapons, including more precise and powerful weapons, present a challenge to a credible deterrence.  New weapons are more capable of conducting strategic missions, such as direct attacks on an adversary’s nuclear arsenal, blurring the line between nuclear and conventional conflict.  This potentially increases the risk of misperception, as an adversary has no idea of the intention behind an attack.  Along with advancements in surveillance, new technologies lead to concerns about the survivability of nuclear arsenals and the ability to maintain second-strike capability, potentially giving adversaries a “use it or lose it” mentality.  If Russia and China, for example, are concerned about US conventional attacks on their nuclear arsenals, they may choose to strike first to reduce the threat.  The increasing number of dual-use delivery systems further complicates things.

 

New low yield nuclear weapons increase the chance of nuclear warfighting and escalation.

 

The Trump Administration’s 2018 NPR (link) cited the need for flexible, tailored deterrence, leading to the development of new low-yield submarine-launched ballistic missiles (SLBMs).  Experts fear this could reduce the threshold for nuclear warfighting, and lead to nuclear weapons being used as a tool of compellence, rather than deterrence.  The president may be more likely to consider using nuclear weapons as a policy tool under the rationale that the benefits outweigh the costs in a limited nuclear exchange.  A more likely scenario is that any nuclear strikes would escalate to full-scale nuclear war.  

 

Proponents of this policy argue that Russia’s “escalate to deescalate” doctrine, where Russia might use smaller-yield tactical weapons in a regional conflict to deter US intervention, necessitate flexible options for the president.  However, escalate to deescalate is not clearly stated nuclear doctrine.   

 

Arms races inherently make for a more dangerous world.

 

For deterrence to work, the threat must be credible, requiring countries to constantly pursue bigger and better weapons.  Arms races are destabilizing to the global order and pose their own security threat.  This affects perceptions and creates unknowns.  In a chicken situation, this could drive countries to perceive that they have a preponderance of power, potentially leading to much greater costs.  Since the US has the ability to destroy a potential adversary’s arsenal, it creates a perverse incentive to use those weapons early to prevent them from being destroyed, creating a destabilizing dynamic that makes nuclear war more likely.

 

Nuclear arms races are also expensive, potentially costing the US trillions of dollars.  The US is currently undergoing an extensive modernization of almost all aspects of its nuclear forces—the Congressional Budgeting Office (CBO) estimates the US will spend $634 billion over the next ten years on modernizing the nuclear arsenal.  Russia and China are also modernizing their arsenals and developing hypersonic glide missiles in an effort to defeat US missile defense systems.