Moving forward, it will be important to address the way in which international security was dealt with during the treaty debate and written into the treaty text—and not just because it has implications for the treaty’s impact, political messaging, and potential for universality. The international security issue showcases more general divisions about whether disarmament measures should be viewed through a deterrence-based lens. In planning next steps for the treaty, non-nuclear weapon states should establish comprehensive dialogues on the role that deterrence-based security dynamics should play in the disarmament process.

International security in the framework of disarmament. During the negotiations that culminated in the July 7 vote by 122 nations in favor of a ban treaty, it was clear that the role of international security in disarmament initiatives had become increasingly controversial. Indeed, this is a primary reason that the five nuclear weapon states recognized by the Nuclear Non-Proliferation Treaty refused to partake in treaty negotiations, and cite regional security concerns as an obstacle to disarmament.

Nuclear weapon states and many of their allies claim that a decision to rely on nuclear deterrence theory—to prevent hostilities between world powers from boiling over into large-scale war—has contributed to international stability. They worry that hasty disarmament of nuclear weapons and disregard for nuclear deterrence will have negative ramifications for the defense policies of alliances, current disarmament agreements, and world peace.

Specifically, the United States, United Kingdom, and France maintain that the ban is incompatible with nuclear deterrence, because it ignores “the realities of the international security environment.” In their view, the treaty doesn’t solve the North Korea problem, implement the Iran deal, or keep contentious world powers from waging war. Because the treaty fails to address regional security, these three nations argue, it could create instability, exacerbate regional tensions, and leave all states feeling more vulnerable and less secure.

Many non-nuclear weapon states are frustrated with the decades-old idea that nuclear weapons provide a stability that enhances security and preserves peace—an idea that has kept the disarmament debate rooted in discussions of security doctrine and balance of forces. They blame it for stalled progress on multilateral disarmament measures, and see it as a distraction from the moral imperative of protecting civilization from any use of nuclear weapons.

This frustration motivated the “humanitarian movement,” which aimed to redirect nuclear weapons rhetoric to focus on their devastating potential to destroy, rather than on their function as deterrents and stabilizers. The movement eventually turned into calls for a prohibition, but it also brought to the forefront disagreements over the role of security concerns in disarmament and how they should be incorporated into the treaty.

A divide among negotiators. The first round of negotiations exposed a division between the states that wanted to engage nuclear weapon states on security concerns while working toward disarmament, and those that questioned the general validity of nuclear deterrence and accused nuclear weapon states of using it as an excuse to expand their arsenals. The vast majority of states wanted to frame the treaty in the context of the destruction that nuclear weapons can inflict, by strongly rooting the preamble in humanitarian and international law. These countries wanted the focus of the treaty to be the devastating potential of these weapons, rather than the theory-based security situations that they’ve created. This is summarized well in a statement from Nigeria: “We remain resolute in our conviction that national security doctrines should not serve to justify the proliferation and the existence of the staggering aggregate of nuclear weapons in the arsenals of [nuclear weapon states].” And in Antigua and Barbados’ statement on behalf of the Caribbean Community, “nuclear weapons have no utility in today’s world. They are not useful deterrents but rather cultivate a state of insecurity and false defensiveness that only increases the chances of proliferation.” These states aimed to not only create a treaty prohibiting nuclear weapons, but also to delegitimize nuclear deterrence and the theories it is based on.

In contrast, a smaller group of non-nuclear weapon states addressed the potential of the ban to affect strategic stability and the nuclear order. Prominent members of this group were mostly European. During the debate on the preamble, these states promoted working with nuclear weapon states to solve regional security threats and advance disarmament. For example, Switzerland’s stated aim was to create a treaty that contributed to disarmament, but that was also “mindful of security challenges” and would “open the door for practical disarmament steps at a later stage.” The Marshall Islands also seemed sympathetic to the security concerns of nuclear weapon states, asserting “disarmament does not occur in a vacuum or on moral principles alone . . . there are complex security issues which are a political reality in disarmament efforts.” Austria and Sweden made similar statements. These states recognize that regional security disputes are an impediment to disarmament, and were hesitant to entirely discount the structures that have been built around deterrence theory.

Why the divide? Why do non-nuclear weapon states that are universally in favor of a nuclear weapons prohibition disagree on the role of international security in this process? The answer is that some of these states could be more affected by larger strategic conflict than others, so they are trying to address security more pragmatically to protect their interests. Despite a true belief in the merits of the treaty, they give weight to the contention of nuclear weapon states that deterrence has maintained a relatively peaceful status quo between major powers since World War II.

This is obviously a concern for the Netherlands, the only NATO member that took part in the negotiations and the only state that voted against the treaty. However, Austria, Switzerland, Sweden and Liechtenstein could also be caught in the cross-hairs of a nuclear conflict between major powers, given their location between NATO and Russia. This is likely why all of them, except Liechtenstein, are members of the Partnership for Peace program, which allows non-NATO states to form bilateral security and defense relationships with the alliance. Though it does not mean they are protected under US extended deterrence, the partnership arrangement has allowed these countries to foster closer coordination with NATO and reap some security benefits. Participation in Partnership for Peace indicates that security concerns and the deterrence posture of NATO are important considerations for these countries; they see value in maintaining these stabilizing ties and the potential to expand them in case of future threats.

Interestingly, the divide on international security correlates to a debate during the negotiations on whether the treaty should include a specific prohibition on the threat of use of nuclear weapons. States in favor of this stipulation argued that an explicit prohibition on the threat of use creates a more comprehensive treaty, reinforces the 1996 International Court of Justice ruling on the threat of use, and delegitimizes deterrence in general. Those states that opposed it, such as Austria, argued that the prohibition was redundant, vague, and potentially damaging to a more general norm set by the UN Charter. Although the final treaty text did include the prohibition, many of the states opposed to it were also those cognizant of international security concerns. They include Austria, Switzerland, and Mexico, which actively spoke against a prohibition on the threat of use; and Ireland, Sweden, and Liechtenstein, which notably left if off their lists of desired prohibitions.

Though it is unclear exactly which states the prohibition is intended to target, it will prevent countries involved in extended deterrence agreements from joining the treaty, and further erode the acceptability and utility of nuclear deterrence. This limits options by NATO states and security-conscious European nations, which is likely why they opposed it. Even states that do not have nuclear weapons stationed on their soil, and are not involved in the sharing of command and control for nuclear weapons stationed elsewhere, will be unable to join the treaty. This closes a potential pathway for NATO members to more easily accede to the treaty, and likely prevents the involvement of states from the Asia-Pacific umbrella or the post-Soviet Collective Security Treaty Organization.

Additionally, this prohibition prevents any states that sign the treaty from joining an extended deterrence arrangement in the future. Naturally, states concerned with the security implications of disarmament may be worried that they could find themselves in the middle of a future dispute between world powers, and may have wanted to maintain the option to join a nuclear umbrella in some form.

Why the divide matters. Many non-nuclear weapon states want to detach any forward motion on disarmament from a framework steeped in international security arrangements. A small, but important, group of non-nuclear weapon states are hesitant to do this. These nations are strategically located, historically involved in disarmament initiatives, and could fund a large portion of the treaty structure. It is not that they are uncommitted to the treaty’s moral underpinnings, but that they are more sympathetic—and some may say more realistic—in acknowledging that there are vital security concerns here that must be addressed.

This division is about more than the language of a preamble, or a prohibition on the threat of use; it is about an increasingly large schism in the international community over the role that security arguments should play in disarmament. For nuclear weapon states, security, balance of forces, military doctrine, deterrence, and disarmament have been intertwined for decades. Treaty supporters are frustrated that multilateral disarmament has become prisoner to this. But the reality is that deterrence will probably continue to be present in international politics until all weapons are dismantled and “general and complete disarmament” is fully achieved.

For this reason, there need to be productive and pragmatic discussions about the degree to which deterrence-based security dynamics should be considered, prior to and during the process of disarmament. These discussions should begin with groups that support the new treaty, as there is still broad disagreement within pro-treaty camps on the validity of nuclear deterrence in maintaining stability.

By systematically analyzing how general disarmament and the ban treaty will affect international security, non-nuclear weapon states can begin to bridge their differences on deterrence. Ideally, this could result in a common understanding among non-nuclear weapon states of how they intend for the new treaty to be integrated into the broader security landscape.

Consensus will not be quick or easy. Simply determining the proper forum and agenda for such a conversation could be difficult. However, without a full assessment of the implications of disarmament for international security concerns, disagreement among non-nuclear weapon states will continue. Only with a united and comprehensive agreement on this issue can non-nuclear weapon states hope to constructively engage nuclear weapon states with this treaty. And without a pathway that can eventually aspire to involve nuclear weapon states, the impact of the treaty as a multilateral approach to disarmament will be limited. Including international security in future disarmament conversations is the next step to making disarmament a commonly shared goal, rather than a divisive and politically fueled controversy.