Editor’s Note: This is an excerpt from “Policy Roundtable: Nuclear First-Use and Presidential Authority” from our sister publication, the Texas National Security Review. Be sure to check out the full roundtable.

Over the past few decades, the United States has weighed the risks and benefits to both its nuclear deterrence posture and its non-proliferation policy goals of renouncing first-use of nuclear weapons in a conflict. In President Barack Obama’s 2010 Nuclear Posture Review and, later, near the end of Obama’s second term as part of a mini-nuclear review, the adoption of a so-called “no-first-use” pledge was considered. Both times, Obama rejected adopting such a policy. The 2018 Nuclear Posture Review carried out by the Trump administration reviewed the policy and reaffirmed Obama’s decision.

Recently, Rep. Adam Smith, the new chair of the House Armed Services Committee, and Sen. Elizabeth Warren have called for a U.S. no-first-use policy. Well-meaning supporters of no-first-use are taken with the simplicity of the idea and its potential for bolstering U.S. “moral leadership” in the world. After all, they argue, the United States has no intention of starting a nuclear war so why not just say so? Given the recent revival of this topic, it is appropriate to review some of the considerations that caused both Obama and Trump, as well as Presidents Bill Clinton and George W. Bus, to reject adopting a policy of no-first-use.

There are three major risks in adopting a nuclear declaratory policy of no-first-use. The first risk is to deterrence: Adversaries, absent a fear of reprisal, could be emboldened to act against U.S. interests. The second risk is to U.S. assurances to its allies: If America adopts no-first-use, then allies could lose confidence in America’s extended deterrence commitments. The third risk is to the goal of non-proliferation: Such lost confidence among America’s allies could spur them to develop and field their own nuclear weapons. The purported benefits of adopting a no-first-use policy, which I discuss below, are insufficient to offset these inherent risks.

Deterrence Risks

Every president since Dwight Eisenhower has viewed nuclear weapons not just as another weapon of war augmenting conventional arms, but as a special kind of weapon to be used only in the direst circumstances when vital U.S. security interests are at stake. The main concern in adopting a policy of no-first-use is that it could lead an enemy to believe that it could launch a catastrophic, non-nuclear strike against the United States, its allies, or U.S. overseas forces without fear of nuclear reprisal. Consider, for example, a North Korean biological attack on an American city that kills hundreds of thousands, or an artillery bombardment of Seoul with chemical weapons, resulting in the deaths of tens of thousands of Korean and U.S. forces and citizens. Would North Korea be more willing to contemplate such attacks if it thought it was immune to a U.S. nuclear response? Recent presidents have been unwilling to accept the risk to deterrence that would accompany a pledge of no-first-use.

Two factors might mitigate such risks to deterrence were a no-first-use policy adopted. First, a no-first-use pledge is unlikely to appear credible to an adversary contemplating major aggression. For example, North Korea is unlikely to base any military planning to reunify the Korean Peninsula by force, or plans for its regime survival after an unsuccessful effort to achieve that objective, on a U.S. promise of no-first-use. Consider China’s existing no-first-use pledge, which has not caused the United States to moderate its own nuclear posture one iota. Few states will risk their national security based on a declaratory policy that can be reversed overnight. Dominic Tierney, an academic who supports a no-first-use policy, eloquently addresses this point:

Viewed through a strategic — and perhaps more cynical — lens, the no-first-use doctrine also has a huge credibility problem. For the U.S. pledge to truly matter, a president who otherwise favors a nuclear first strike would have to decide not to press the button because of this policy. But in an extreme national crisis — one involving, say, North Korean nuclear missiles — a president is unlikely to feel bound by America’s former assurance. After all, if a country is willing to use nuclear weapons, it’s also willing to break a promise.

Second, it’s not at all clear that an adversary could count on U.S. public opinion to act as a “brake” on an American president contemplating first use in response to a catastrophic non-nuclear attack. Several surveys conducted by Scott Sagan and Ben Valentino look at the American public’s willingness to support first-use under such circumstances. The results reveal a surprising level of support. Sagan and Valentino thus argue:

Would we drop the bomb again? Our surveys can’t say how future presidents and their top advisers would weigh their options. But they do reveal something unsettling about the instincts of the U.S. public: When provoked, we don’t seem to consider the use of nuclear weapons a taboo, and our commitment to the immunity of civilians from deliberate attack in wartime, even with vast casualties, is shallow. Today, as in 1945, the U.S. public is unlikely to hold back a president who might consider using nuclear weapons in the crucible of war.

In other words, the American public might well demand, rather than oppose or simply tolerate, a nuclear response to a catastrophic non-nuclear attack — no-first-use pledge or not.

Thus, an adversary’s doubts about a no-first-use pledge and its belief that the U.S. public may well support breaking such a pledge in response to a horrific attack could mitigate some of the deterrence risks of adopting a no-first-use policy. However, the degree to which those risks would be mitigated remains uncertain and, so far, no president has been willing to find out.

Assurance and Nonproliferation Risks

Building and maintaining strong alliances has been a centerpiece of America’s effort to produce and sustain a more peaceful world. Critical to this is assuring U.S. allies of America’s commitment to their defense by extending to them the full range of U.S. military power.

Many countries, including those that share a border with an adversary that presents a threat to their very existence, see no-first-use as a weakening, symbolic or otherwise, of U.S. extended deterrence. In response to Chinese provocations in the western Pacific and North Korea’s nuclear tests and missile launches, Japan regularly seeks, both in official consultations and ongoing military cooperation, assurances that America will continue to fulfill its security commitments to protect the island nation. Some in South Korea have already pressed to explore an increased U.S. nuclear presence in their country to further deter regional threats. Loss of confidence in U.S. security commitments could cause some allies to seek accommodation with regional adversaries in ways that run counter to U.S. interests.

Moreover, both South Korea and Japan, similar to many NATO allies, have latent nuclear weapons capabilities characteristic of advanced industrial economies with commercial nuclear power. Any perceived wavering of U.S. security commitments could cause allies to develop and field their own nuclear weapons.

Further, America’s allies have made their feelings about America adopting a no-first-use policy known. U.S. officials consulted America’s allies extensively in the lead up to the 2010 and 2018 nuclear posture reviews. This dialogue has been rich and productive and, in some ways, surprising in its candor. For example, in 2009, Japanese officials briefed the Perry-Schlesinger Commission, established by Congress to seek a bipartisan approach to the U.S. nuclear posture, on specific features and capabilities of the U.S. nuclear deterrent that Japan viewed as critical to its security. In related dialogue, many foreign counterparts to U.S. officials, including those of Japan, have urged the United States not to adopt a no-first-use policy.

Supposed Benefits of a U.S. No-First-Use pledge

In light of these risks, what are the benefits of a U.S. no-first-use pledge that could offset them? Would it, as Sen. Warren claims, “[reduce] the risk of a nuclear miscalculation by an adversary in a crisis … ”? If an adversary launches a nuclear weapon because it has misinterpreted America’s actions or intentions, or even if it launches a nuclear weapon by accident, the consequences would, of course, be tragic. Such actions must be assiduously avoided with clear crisis communications, transparency, and strong negative control of nuclear weapons. But, a U.S. no-first-use pledge, by itself, is unlikely to have any effect at all in preventing such a situation from arising in the first place.

Some argue that adopting such a policy would set an example and cause nuclear adversaries to follow America’s lead. If promises were kept, this would allow the U.S. conventional juggernaut to win wars absent the threat of nuclear use. But this outcome is unlikely. Indeed, several nuclear adversaries have acquired, or are currently seeking, nuclear weapons precisely to offset superior U.S. conventional capabilities. Again, quoting Tierney:

“If [a President] made a dramatic announcement of no-first-use, it would probably have less impact than people think because other countries wouldn’t follow suit, especially if they’re weak.”

Would U.S. adoption of no-first-use cause other countries to be more inclined to cooperate with the United States to work toward a strengthened nonproliferation regime and less likely to acquire nuclear weapons of their own? No evidence exists to support such a contention and, as noted above, allied perceptions of weakened extended deterrence could actually spur proliferation.

Another purported benefit of adopting a no-first-use policy is that it might silence criticism from Non-Aligned Movement countries that periodically denounce the United States for, among other things, not having disarmed unilaterally. This is unlikely. Indeed, the enormous progress made in the decades leading up to the end of the Cold War and beyond in ending the nuclear arms race, reducing nuclear stockpiles, and eliminating other global nuclear threats has done little to moderate such rhetoric.

Along these lines, some view no-first-use as a means to delegitimize nuclear weapons in general, and, more specifically, as a first step to removing from alert and eventually getting rid of the inter-continental ballistic missile (ICBM) leg of the Triad. After all, if ICBMs are not survivable unless used first, and if America’s policy becomes one of no-first-use, then why does the United States need them at all, much less on alert? This claim misrepresents both the role of America’s ICBMs and the obligations that America would be under as part of a no-first-use pledge. Thus, such arguments are unlikely to sway any president who views a nuclear Triad as an essential element of U.S. security for managing risk in a dangerous world.

Many who favor a U.S. no-first-use pledge see it as a way to signal to the world a reduced role for nuclear weapons in U.S. national security. Reducing that role, and hence the likelihood that the United States would ever have to resort to nuclear use, is a laudable goal advanced in the nuclear posture reviews of the three previous presidents. But, in regard to its foreign impact, the actual security benefits that could justify accepting the risks of this policy are not well understood, nor are they quantifiable, and so far they have not tipped the scales toward the adoption of no-first-use.

Those who support no-first-use as a way to advance U.S. security must explain what has changed for the better in the international security environment since 2010 that would cause this president, or this Congress, to reverse earlier presidential decisions rejecting it.

Conclusion

It has been a precept of U.S. policy for decades that deterrence is strengthened when an adversary is unsure of the precise conditions under which the United States would employ nuclear weapons — essentially, that uncertainty breeds caution. America has made exceptions, however, in certain cases to advance concrete security interests — for example, in regard to nuclear negative security assurances provided to non-nuclear weapons states that are parties in good standing with the Nonproliferation Treaty. If the United States were to adopt a policy of no-first-use, it would present clear risks for deterrence, for regional security more broadly, and to the non-proliferation regime, while the supposed benefits of such a policy that could offset such risks are largely illusory. It is thus no surprise that since the dawn of the nuclear age presidents across party lines have rejected no-first-use. The United States should continue to do so.

Dr. John R. Harvey is a physicist who has spent his career working to advance U.S. nuclear weapons programs and policies including in senior posts in the Departments of Energy and Defense. He retired from government service in 2013 as principal deputy assistant secretary of defense for nuclear, chemical, and biological defense programs.

Image: National Nuclear Security Administration photo courtesy of Nevada Field Office