The new nuclear threat: Belarus 

On Sunday, Belarus issued a statement that it would use nuclear weapons if its “sovereignty and independence” were threatened. But would such a use violate international law? 

The question breaks down into a few sub-questions, the first of which is how Belarus, Russia’s ally in the region, obtained nuclear weapons in the first place. The answer, of course, is that they came from Russia. From there, one must ask whether the stationing of nuclear weapons in Belarus and the training of Belarusian soldiers in the use and operation of such weapons is a violation of international law. 

Here the relevant international law comes from the Treaty on the Nonproliferation of Nuclear Weapons, to which both Belarus and Russia are party. Article I of the treaty prohibits “the transfer to any recipient whatsoever [of] nuclear weapons or other nuclear explosive devices or control over such weapons,” and Article II prohibits “receiv[ing] the transfer from any transferor whatsoever of nuclear weapons or other nuclear explosive devices or of control over such weapons.” 

It would not be unreasonable at first glance to conclude that Russia’s stationing of the weapons violates the treaty. But there is strong precedent that it does not.  

This precedent comes from the longstanding practice of the U.S. and NATO in what are referred to as nuclear “sharing arrangements,” whereby the U.S. stations nuclear warheads in allied countries. The U.S.-NATO argument that such arrangements are legal under the non-proliferation treaty is that the weapons remain at all times under the control of the U.S., thus not violating (or perhaps more accurately not triggering) the treaty. Russia’s stationing of the weapons in Belarus appears to be likewise legal under international law.  

What is more questionable is whether use of the weapons by Belarus — not Russia — would violate the nuclear treaty. As soon as control of the weapons is transferred to Belarus, Article I and II of the treaty are triggered, thus constituting a violation of international law. 

The other obvious question is whether the use of such weapons violates international law. Here Belarus is likely relying upon Article X of the treaty, which states: “Each Party shall in exercising its national sovereignty have the right to withdraw from the Treaty if it decides that extraordinary events, related to the subject matter of this Treaty, have jeopardized the supreme interests of its country.”

It is no accident that Belarus’ statement contains similar language to Article X, stressing state “sovereignty.” 

But a threat to sovereignty is highly subjective. Does international law provide a mechanism by which states may gauge the legitimacy of a purported threat?

The answer is yes. Article X sets out that a state withdrawing from the non-proliferation treaty “shall give notice of such withdrawal to all other Parties to the Treaty and to the United Nations Security Council three months in advance. Such notice shall include a statement of the extraordinary events it regards as having jeopardized its supreme interests.”

Here, international law provides an objective constraint on the use of nuclear weapons and an opportunity for the international community to come together and define what does, and does not, constitute a valid threat to state sovereignty freeing states to use nuclear weapons. 

Belarus’s statement is a warning. It is now up to the world to respond. 

Anthony J. Colangelo is the Robert G. Storey Distinguished Faculty Fellow and Professor of Law at the Dedman School of Law, SMU Dallas.