Foreign Relations & International Law

Constructive Ambiguity of the Budapest Memorandum at 28: Making Sense of the Controversial Agreement

Mykhailo Soldatenko
Tuesday, February 7, 2023, 8:00 AM
The 1994 Budapest Memorandum was purposefully designed to be ambiguous to allow its signatories to achieve significant goals. It is an important tool in the discourse on the current war waged by Russia in violation of the memorandum.
U.S. President Clinton, Russian President Yeltsin, and Ukrainian President Kravchuk after signing the Trilateral Statement on Jan. 1994.
U.S. President Clinton, Russian President Yeltsin, and Ukrainian President Kravchuk after signing the Trilateral Statement on Jan. 1994. (U.S. government employee,; Public Domain,

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Last December marked the 28th anniversary of the Budapest Memorandum, in which the United States, the United Kingdom, and Russia provided security commitments to Ukraine in exchange for the latter joining the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) as a non-nuclear state. As part of the agreement, Ukraine relinquished the third largest nuclear arsenal in the world (which it inherited from the U.S.S.R.) and Russia agreed (among other things) “to respect the independence and sovereignty and the existing borders of Ukraine” (emphasis added). 

Today the Budapest Memorandum is considered by many to be a grave diplomatic blunder in light of the brutal war Russia has waged in violation of it. Ukraine’s head of the Office of the President, Andriy Yermak, summed up the conventional view when he called the document “ill-fated” and concluded: “Never again. No more Budapest Memorandums.” 

Although the memorandum did not prevent Russia’s invasion, it helped its signatories achieve important goals and is a significant tool in the discourse on the current war, highlighting the broken promise of security in exchange for Ukraine giving up its nuclear weapons. Whether the memorandum is a treaty binding under international law or merely a political deal is the subject of vigorous debate, but the parties purposefully left this issue ambiguous to make the agreement possible in the first place. 

Security Deadlock 

One of the major factors in Ukraine’s decision to relinquish its nuclear weapons was the pressure from the United States and Russia involving risks of potential isolation and dire consequences for the staggering Ukrainian economy. But Ukraine was not willing to give up its nuclear arsenal just because of this pressure. In nuclear disarmament negotiations, Ukraine requested compensation and legally binding security guarantees from the United States and Russia as a substitute for the nuclear deterrent. The security request was especially acute due to Russia’s constant pretensions over Crimea following the collapse of the U.S.S.R. For example, in 1993, the Russian Parliament declared Russia’s alleged sovereignty over the Ukrainian strategic port city of Sevastopol while negotiations about the security commitments were still ongoing.

Following protracted negotiations, the parties agreed that Russia would provide compensation to Ukraine via nuclear fuel rods and energy debt write-offs. The United States also agreed to finance Ukrainian disarmament via the Nunn-Lugar Program, which involved the appropriation of funds from the U.S. defense budget to assist the former Soviet republics in securing and dismantling the nuclear weapons.

However, the security issue proved to be the thorniest in negotiations, considering the Ukrainian Parliament’s refusal to sign off on nothing less than legally binding security guarantees, as well as the United States’s and Russia’s joint resistance to Washington’s ironclad security guarantees to former Soviet republics akin to ones the United States provides to its allies. The deliberately ambiguous Budapest Memorandum paved the way out of this deadlock. 

The Memorandum’s Design 

What Was Promised? 

In the memorandum’s text, the guarantors reaffirmed the following legal and political commitments already existing elsewhere. 

First, they reaffirmed their commitments under the 1975 Helsinki Final Act, which is widely considered a political instrument. Namely, they agreed “to respect the independence and sovereignty and the existing borders of Ukraine” (emphasis added) as well as “to refrain from economic coercion designed to subordinate to their own interest the exercise by Ukraine of the rights inherent in its sovereignty and thus to secure advantages of any kind.” 

The importance of the wording “the existing border[]”—which was put into the memorandum  at Ukraine’s request—is often missed in public discourse. This phrase was crucial for Ukraine to receive direct and unconditional confirmation from Russia, along with other signatories, of its sovereignty over all territories it possessed within the Soviet Union, including Crimea. In earlier agreements (see Article 5 of the so-called Belavezha Accords), Russia confirmed Ukraine’s borders only within the Commonwealth of Independent States (CIS) and wanted to repeat that qualifier in the memorandum. Ukraine viewed that position as a nonstarter in light of Russia’s significant influence over the CIS. The Budapest Memorandum was the first international agreement to iron out this issue.

The parties also reaffirmed obligations under Article 2(4) of the U.N. Charter “to refrain from the threat or use of force against the territorial integrity or political independence of Ukraine[.]”

And they reaffirmed the positive and negative security assurances to all non-nuclear states under the NPT previously made by nuclear powers, including Russia, the United Kingdom, and the United States. Namely, they pledged:

to seek immediate UN Security Council action to provide assistance to Ukraine if it should become a victim of an act of aggression or an object of a threat of aggression in which nuclear weapons are used” and “not to use nuclear weapons against any non-nuclear-weapon state … except in the case of an attack on themselves, their territories or dependent territories, their armed forces, or their allies by such a state in association or alliance with a nuclear weapon state.

Besides the wording “the existing border[]”, another novelty in the memorandum’s text was the parties’ procedural commitment (in paragraph six) to conduct joint consultations in a situation that “raises a question concerning [substantive] commitments.” This addition was highly valuable to newly independent Kyiv, because it granted Ukraine the potential ability to have the United States and the United Kingdom engaged in its conversations with Russia on any present and potential security threats covered by the memorandum. This commitment was certainly not something that Ukraine could take for granted. For instance, former senior Ukrainian diplomat Oleksandr Chalyi reported that the invocation of this commitment and the ensuing informal consultations between Ukrainian, Russian, and U.S. diplomats were instrumental in resolving the 2003 Tuzla Island crisis between Russia and Ukraine. 

Additionally, Ukrainian and U.S. negotiators Borys Tarasyuk and Steven Pifer recalled that in the discussions about the Budapest Memorandum, U.S. negotiators promised orally that the United States would take a strong interest and respond to any Russian violations of the agreement or the “memorandum’s spirit.” While the United States’s verbal promise can be considered as an understanding of its commitments under the agreement or an oral security commitment adjacent to the memorandum, there is no public information about who made this specific commitment or about the precise scope of the response the U.S. negotiator had mentioned at the time. However, according to Pifer, who later served as U.S. ambassador to Ukraine, while the parties allegedly did not discuss details of the U.S. response under this commitment, in his opinion, the response should involve military assistance. 

It is also equally important to acknowledge what was not agreed upon in the memorandum. For example, the memorandum could have contained Ukraine’s commitment to remain neutral between NATO and Russia or put clear limits on foreign support in case of the agreement’s breach, which would negatively impact Ukraine’s and its supporters’ position in the current war. 

Although the memorandum’s text primarily reaffirmed the preexisting commitments of the guarantors, the parties still disagreed on whether to make it a binding treaty or a political deal, and debates on this matter continue to this day. 

Treaty or Political Deal? 

Although enforcement mechanics of legal and political agreements may be similar in many situations, the independent significance of legally binding commitments is explained by—all things being equal—their stronger credibility and higher violation costs. States and the public generally attach particular weight to them, and international law provides legal responsibility for their violation. That does not mean that states do not take political commitments seriously because their breach, as with any other promise, puts their reputation and credibility at stake. However, it is often much easier for states to justify and mitigate the reputational costs of their violations. (For example, see former President Trump’s exit from the Joint Comprehensive Plan of Action.) Thus, the reluctance to agree on a treaty reveals a lot about the extent of states’ resolve—or lack thereof—to comply in the future. 

Accordingly, the Ukrainian Parliament strongly conditioned Ukraine’s accession to the NPT on the “international legal document,” something that the guarantors (and potentially their parliaments) were not comfortable with. The guarantors’ resistance is explained, among other things, by the fact that the binding nature of the memorandum may have transformed otherwise political commitments (under the Helsinki Final Act and NPT-related security assurances) into legal obligations under international law. And the consultation procedure to discuss any breaches of the memorandum would also be legally binding. 

To resolve this dilemma, the signatories designed the memorandum’s text in such a way that it could be reasonably interpreted both as a treaty under international law and as just a political deal. Ukraine could treat the memorandum as a treaty, among other things, for the NPT ratification by its parliament, while the guarantors reserved the opportunity to claim its political nature. 

International law provided the signatories with perfect conditions to do so. An international practice can be divided roughly into two tests to define when states intended an agreement to be “governed by international law” under the 1969 Vienna Convention on the Law of Treaties (VCLT). While both tests examine the same factors—such as the agreement’s text, substance, and conditions of conclusion—the difference lies in the primacy of either actual intent (intent test) or its objective manifestation (objective test). There is no uniformity between international tribunals on the uniform criteria in this regard, let alone between states. Things are complicated further by the fact that a binding agreement may contain political commitments. 

Against this legal background, the states constructed the ambiguous wording, among other things, by putting different terms in equally valid English, Ukrainian, and Russian texts. Namely, Ukrainian and Russian texts were not just translations but, rather, authentic texts of the memorandum on a par with the English text. 

First, the text of the agreement does not explicitly define the nature of the agreement. The signatories specified neither its binding nor political nature, which is usually done when the parties want certainty on the matter. (For example, see the NATO-Russia Founding Act, which specifically mentions the political nature of commitments set forth therein.) 

Second, the parties called the document a “memorandum,” which is a label for both legal and political agreements. The VCLT provides that an agreement can be a treaty regardless of “its particular designation.” At the same time, directly calling the document a “treaty” would have strongly supported its legal nature, while the term “memorandum” is often perceived as nonbinding, especially beyond expert circles. When the term “memorandum” was presented to the Ukrainian Parliament, some members voiced concerns that it meant “we sat, chatted, and that’s it.” More recently, then-President Trump publicly debated the meaning of this term with U.S. Trade Representative Robert Lighthizer, arguing that memorandums “don’t mean anything.” Therefore, the “memorandum” label is a good choice on the part of the signatories for constructing ambiguity.

Third, the English version mentions “security assurances,” while Ukrainian and Russian texts provide for “security guarantees.” This different wording is often explained by the fact that in Ukrainian and Russian, the words “assurances” and “guarantees” are allegedly considered to be synonyms. However, there are much better, more accurate substitutes for “assurances” in Ukrainian and Russian, namely “запевнення” and “заверения.” The parties likely put different terms in different languages to create ambiguity. In retrospect, the Ukrainian Parliament probably would not have agreed to the term “assurances,” because “guarantees” represent something definitely more substantial. As a matter of international law, both terms can potentially signify political and legal obligations with varying degrees of obligations up to military support. For example, in 1975, President Nixon provided South Vietnam with “absolute assurances” of U.S. “swift and severe retaliatory actions” “with full force.” Still, the word “guarantee” is customarily used with more robust commitments like those provided within military alliances and mutual defense treaties. The particular caution of U.S. diplomats toward the use of “guarantees” in diplomatic discourse (when clear legal obligations are not at issue) is exemplified by the following comment on Iran’s request for potential guarantees of nonrepudiation of the Iran nuclear deal: “There is no such thing as a guarantee; that’s not in the nature of diplomacy.”

Fourth, the Budapest Memorandum’s Ukrainian version provides that it “enters into force upon signature.” The International Court of Justice found this specific wording to be an “indicator” of a legally binding memorandum without the need for ratification. However, English and Russian versions provide an iterated softer language that the memorandum “will become applicable upon signature,” which contributes to its ambiguity. 

There are important factors beyond the text as well. For example, the Ukrainian Parliament, while ratifying the NPT, made a reservation to condition the ratification law’s “entry into force” on “the provision of security guarantees to Ukraine by nuclear states via signing the international legal document” (the emphasized term was specifically inserted instead of “memorandum” following the deliberations). Without this specific reservation, the parliament may not have ratified the NPT in the first place. This wording heavily advocates in favor of the legal nature. If the memorandum is not legally binding, Ukraine’s consent to the NPT was potentially deficient as a matter of not only domestic law but international law as well due to the mentioned reservation. In short, the ambiguity of the memorandum’s nature potentially infected Ukraine’s consent to the NPT. 

Following Russia’s aggression in 2014, Ukraine submitted the Budapest Memorandum for treaty registration under Article 102 of the U.N. Charter to support the memorandum’s legal nature. The U.N. subsequently registered and published it as a treaty on Oct. 2, 2014. While this is an important factor in defining the memorandum’s nature, the U.N. secretariat’s decision to register an instrument as a treaty is not determinative in this respect since the secretariat does not conduct the necessary inquiries to analyze all the relevant factors mentioned above. Notably, the secretariat takes the position that its registration “does not confer on the instrument the status of a treaty or an international agreement if it does not already have that status.” However, in Somalia v. Kenya, the International Court of Justice found that the registration and the prolonged absence of objections to it from other parties contribute to the memorandum’s binding nature. Thus, the non-objection of the United States and the United Kingdom to the binding nature of the Budapest Memorandum and its registration in the U.N. is an important factor in favor of its bindingness. 

According to Pifer, the United States allegedly communicated its intention to have only political commitments to its counterparts, and the State Department’s lawyers wanted to ensure that the agreement’s English wording signified political commitments only. These efforts, however, do not shatter the ambiguity of the document, especially in light of the Ukrainian Parliament’s direct reservations to the contrary, the U.N. registration, and if the objective factors are preferred over the post-factum observations similar to those disregarded by the International Court of Justice in Qatar v. Bahrain

Practical Implementation 

The ambiguous memorandum helped the parties to reach important political objectives in the past, including significantly contributing to the non-proliferation regime as well as foreign assistance to and cooperation with Ukraine. 

The document is far from being a robust security pact, but it is by no means just window dressing. The memorandum explicitly conveys a quid pro quo agreement between Ukraine and the nuclear states: promised security for giving up the nuclear weapons, which is a significant tool in today’s discourse on Russia’s aggression. 

First, the memorandum is an important basis for isolating Russia in international politics, especially for the country’s violation of a specific security promise to Ukraine and the related corrosive effect on the non-proliferation regime. The state that gave up its nuclear weapons for the security commitments is now being attacked by one of the guarantors, which is also leveraging its nuclear status. The memorandum helps to build a convincing position for resisting Russia’s aggression based on its breach by emphasizing the importance of keeping promises (whether legal or strictly political) in international relations, and highlighting a destructive message such a breach of the agreement sends—if unaddressed—to potential nuclear proliferators. Ukraine, the United States, and other states have appealed the memorandum to galvanize resistance to Russia’s invasion, and the U.N. General Assembly adopted resolutions to address Russia’s unlawful actions that referenced the memorandum.

Second, the memorandum serves as a convincing argument in favor of supporting Ukraine against Russian aggression, including with lethal weaponry. The United States and the United Kingdom must aid Ukraine in its ongoing war with Russia because of the memorandum’s quid pro quo nature involving the two countries, adjacent oral promises of the United States (as described above), and the strong desire to safeguard the viability of the non-proliferation regime. Some U.S. policymakers have already relied on this memorandum as part of their reasoning for supporting Ukraine. For example, Sen. Ted Cruz (R-Texas) delivered a speech on the floor of the U.S. Senate in which he affirmed that the United States has a “formal obligation to support Ukraine” under the Budapest Memorandum. 

Third, Ukraine is using the Budapest Memorandum’s failure to make a convincing argument that its security environment must be upgraded. Ukrainian policymakers argue that because Russia is not holding up its end of the deal, while Ukraine had done its part by giving up its nuclear weapons, Ukraine is entitled to a security substitute for the memorandum either in the form of ironclad guarantees or the return of the nuclear deterrent, such as NATO membership. 

As part of its 10-step peace plan, Ukraine seeks to receive legally binding security guarantees sufficient to deter and repel Russia’s aggression. This proposal is known as the Kyiv Security Compact and is specifically framed as an antithesis to the Budapest Memorandum. 

Even before Russia’s full-scale invasion in February 2022, President Zelenskyy alluded to another potential option to fix the issue: withdrawal from the NPT. Given Russia’s aggression, Ukraine has a convincing legal position for doing so under Article 10 of the NPT, which states that “[e]ach 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.” This is especially true considering the Ukrainian Parliament’s reservations to the NPT that Ukraine would consider any threat or use of force against it by a nuclear power as “extraordinary events jeopardizing its supreme interests.” 

The ambiguity of the memorandum’s nature led to a situation in which different actors are plausibly trying, depending on their vantage point, to either increase the importance of their positions by claiming the agreement’s legal nature, downplaying them by calling it a political instrument, or just concentrating on the breached promise without mentioning its nature. 

Specifically, Ukraine often claimed that the memorandum is binding, to strengthen its position or avoid specifying the breached obligations’ nature. However, for example, in 2010, while asking for a robust security substitute for the memorandum, the Ukrainian Parliament noted that the memorandum contains “political obligations,” potentially stressing the need for a robust substitute. 

In turn, Russia tried to downplay the memorandum’s importance by calling it a “political declaration” that did not create any new obligations under international law. But notably, Russia has never withdrawn from it. 

In turn, U.S. officials avoided clarifying the memorandum’s nature, likely to maintain its ambiguity. More recently, U.S. Secretary of State Antony Blinken avoided directly answering a reporter’s query about whether the United States confirms any “legal obligations” to Ukraine under the memorandum, saying only that the United States “stand[s] very much behind that support … expressed in the Budapest Memorandum.”

In sum, ambiguity made the Budapest Memorandum and its goals possible by allowing the parties to agree to disagree about its nature and the exact scope of the guarantors’ actions in case of its breach. While it failed to prevent aggression, the quid pro quo agreement is still better than nothing considering its useful and active application in the public discourse on the current war.

Mykhailo Soldatenko is a visiting researcher on international agreements at Harvard Law School and a transitional justice researcher at Harvard Kennedy School’s Carr Center for Human Rights Policy. Mykhailo is also an attorney at law in Ukraine and New York and a Ph.D. candidate in public international law at Kyiv-Mohyla Academy. He was previously a senior associate at the Asters law firm in Kyiv, where he practiced international dispute resolution.

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