To date, US nuclear doctrine has worked; no one has launched a nuclear attack on the United States, or anyone else, since the end of World War II.
Nuclear war is one of the world’s most pressing existential threats, and perhaps the most immediate extinction-level threat posed to humankind. Holding one of the world’s largest nuclear stockpiles is the United States—which maintains a posture of calculated ambiguity on its nuclear policy, making it extremely difficult to know how and when America might deploy its nuclear weapons. Yet despite US doctrinal ambiguity, precedent and procedures offer some insights into the true nuclear policies of the world’s most powerful nation.
The Goal of America’s Nuclear Arsenal Is Deterrence
Some nuclear weapons states have obtained nuclear weapons as a way to account for shortfalls in their conventional forces. For example, Pakistan’s military is widely considered to be weaker than India’s, but Pakistan’s possession of nuclear arms helps to maintain a balance of power between the two sides.
The United States has long had the world’s strongest conventional forces, eliminating the need for nuclear reliance as a shield. Instead, the foundation of US nuclear doctrine is nuclear deterrence—meaning the highest priority is the prevention of adversary nuclear aggression through the looming threat of cataclysmic retaliation. Since the advent of the nuclear age in the 1940s, the United States has sought to convince foes that any nuclear attack on the US or a treaty ally would qualify for a retaliatory nuclear strike of immense proportions.
Of course, America’s deterrence capability relies heavily upon its ability to execute a second strike, requiring the maintenance of a diverse and diffused nuclear arsenal. One might argue that this deterrence strategy has worked: after all, no one has ever launched a nuclear strike against the United States.
“Flexible Response”: US Strategic Doctrine Since 1961
During the 1950s, the administration of President Dwight D. Eisenhower adopted a policy of “massive retaliation” with regard to nuclear use—essentially the threat that the United States would use nuclear force in response to any provocation. In the late 1950s, however, a series of incidents unfolded around the world that this approach was unable to deal with—chiefly because it would have required the United States to escalate to nuclear war, a step that Eisenhower was repeatedly unwilling to take.
After President John F. Kennedy took office in 1961, US policymakers have adopted a doctrine of
flexible response,” which allowed for a spectrum of response options—everything from conventional defense to limited nuclear use. The purpose of this approach has been to give policymakers a slew of credible choices that fall short of an all-out nuclear war—a commendable decision, given that all-out nuclear war potentially ends in the termination of humankind. To that end, the US continues to maintain a range of nuclear systems that allow for proportionate responses short of all-out nuclear war: namely, its nuclear triad.
The most recognizable feature of the US nuclear doctrine is the nuclear triad, consisting of:
- Land-based ICBMs, for quick-response capabilities);
- Nuclear-armed attack submarines that are virtually impossible to eliminate in a first strike, offering stealth and second-strike capabilities; and
- Nuclear-armed bomber aircraft, offering maximum flexibility.
The triad ensures that no single strike can disarm the US nuclear arsenal—which signals to adversaries that any nuclear strike against the United States will result in a retaliatory strike that will annihilate the attacking nation, making the first strike a losing proposition.
Calculated Ambiguity on Nuclear Use
As previously mentioned, the US maintains a posture of calculated ambiguity. For example, the US has never adopted a universal “no first use” pledge, instead allowing adversaries to guess over exactly how and when the US may choose to use their formidable nuclear arsenal. This ambiguity leaves open, for instance, the possibility that America would choose to retaliate with nuclear weapons against a sufficiently damaging conventional attack. It also makes no reference to whether nuclear weapons would be used in response to other weapons of mass destruction, namely biological and chemical agents.
Official US doctrine calls for minimizing civilian casualties during a nuclear attack, instead focusing more strictly on military targets. However, the scale of nuclear weapons inevitably causes massive collateral damage, rendering the point somewhat moot.
To date, the composite US nuclear weapons doctrine has worked: no one has ever launched a nuclear attack on the United States (or anyone else) since the US dropped atomic weapons on Hiroshima and Nagasaki in 1945. Extending this streak into the 21st century—with the United States and Russia at loggerheads, and with the rise of China’s increasingly sophisticated nuclear arsenal and North Korea and Iran as potential nuclear spoilers—will require navigating new challenges. Similarly, the rise of cyber threats and artificial intelligence add another layer of uncertainty in a world, with weapons, where simple error could cause extinction.
About the Author: Harrison Kass
Harrison Kass is a senior defense and national security writer at The National Interest. Kass is an attorney and former political candidate who joined the US Air Force as a pilot trainee before being medically discharged. He focuses on military strategy, aerospace, and global security affairs. He holds a JD from the University of Oregon and a master’s in Global Journalism and International Relations from NYU.
Image: Shutterstock / Paul R. Jones.
