The nuclear ban treaty and legal leverage for its supporters

Editor’s note: This article is part of a collection to mark the occasion of the entry into force of the Treaty on the Prohibition of Nuclear Weapons.

The entry into force of the Treaty on the Prohibition of Nuclear Weapons (TPNW) is a legal game-changer. The legal leverage that non-nuclear armed states lost in 1995, when the Nuclear Non-Proliferation Treaty (NPT) was indefinitely extended, will be regained.

When the NPT was indefinitely extended in 1995, the non-nuclear armed states lost legal leverage within that forum to get the nuclear armed states to give up their weapons. Article 10 paragraph 2 of the NPT limited the initial duration of the treaty to 25 years, after which members had to decide by majority vote whether to extend the treaty indefinitely or for a fixed period or periods. This provision was included precisely to give non-nuclear armed states some leverage to hold nuclear weapon states to their Article 6 obligations: cessation of the nuclear arms race and nuclear disarmament.

If there had been periodic votes to extend the treaty, such as the option of 25-year rolling extensions proposed in 1995, the non-nuclear armed states could have used those to extract concessions from the NPT’s five nuclear armed states. Instead, because it was extended forever, the NPT became a status quo treaty, extending the legality of nuclear weapons in practice indefinitely too. Worse, the promises made at the 1995 conference to secure indefinite extension by consensus and at subsequent review conferences are simply not being kept despite their binding nature.

As we know, as long as some states get to have nuclear weapons, others may come to feel they need them too. Under the NPT, nuclear disarmament can be continually postponed, and because of that the NPT has become a weak and dangerous instrument for nonproliferation. It has no normative power left; only coercive power of the hypocritical kind: Do as we say, not as we do, or else.

The only legal recourse that non-nuclear armed states have left to challenge this outcome is to threaten withdrawal from the NPT. But, the majority of non-nuclear armed states do not want nuclear proliferation any more than they want the nuclear armed states to continue having nuclear weapons. Withdrawal from the NPT would also make their peaceful programs suspect and subject to the hypocritical harassment of those with nuclear weapons. So the threat to withdraw from the NPT is inadequate as a form of leverage.

In January 2021, when the TPNW enters into force, that will change. Non-nuclear armed states will have regained the legal leverage that they had lost in 1995. They will have an alternative legal instrument to affirm and verify their commitment to nonproliferation and to further nuclear disarmament. They will not have to belong to an NPT that in practice legitimizes nuclear weapons—not just for the NPT’s five nuclear armed states, but by their example for all states.

The TPNW is clear: Nuclear weapons are inhumane. Over time, the treaty will stigmatize nuclear weapons and their possessors and strengthen the legal case for abolition. Hopefully, the only effect of the unacceptable pressure that the United States has put on non-nuclear armed states not to support the ban treaty will be that they exercise their legal leverage sooner rather than later.