Ottawa Treaty and the Convention on Cluster Munitions: Recent developments

Approximate read time: 15 minutes

On 3 April 2025, the House of Lords is scheduled to debate the following motion:

Lord Verdirame (non-affiliated) to ask His Majesty’s Government what assessment they have made of the announcement by NATO allies, including Baltic states and Poland, that they intend to withdraw from the Ottawa Treaty on anti-personnel landmines and the Convention on Cluster Munitions.

1. Ottawa Treaty

1.1 Overview

Widely referred to as the Ottawa Treaty, the Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-personnel Mines and on their Destruction is an international agreement that bans anti-personnel landmines.^[1] Landmines predominantly come in two varieties: anti-personnel and anti-vehicle mines. Both types have caused harm to civilian populations and continue to kill and injure long after conflicts end.^[2]

The Ottawa Treaty bans anti-personnel mines, which it defines as those “designed to be exploded by the presence, proximity or contact of a person and that will incapacitate, injure or kill one or more persons”.^[3] This definition is set out domestically in the UK in section 1 of the Landmines Act 1998. The 1998 act also enabled the then government to ratify the treaty. Anti-vehicle mines are not banned by the treaty, which also allows state parties to retain a limited number of anti-personnel mines for training and clearance purposes.

1.2 Recent use of anti-personnel mines in Ukraine

The International Campaign to Ban Landmines’ (ICBL) ‘Landmine monitor 2024’ reported that Russia has used anti-personnel mines extensively in Ukraine since launching its full-scale invasion of the country in February 2022.^[4] The ICBL said that this had led to an unprecedented situation where a country that is not party to the Ottawa Treaty (Russia) is using the weapon in a country which is a state party (Ukraine).

In October 2024, the UN reported that Ukraine had become the most mined country in the world, with potentially 23% of its land at risk of contamination from landmines and unexploded ordnance.^[5] It said that following three years of full-scale war, Ukraine is estimated to be “littered with hundreds of thousands of explosive remnants of war”. As of August 2024, the UN said that there had been around 1,286 civilian victims of mines and explosive remnants.

In May 2023, the then UK defence secretary, Ben Wallace, spoke about Russia’s use of anti-personnel mines in Ukraine and warned about the long-term impact:

Moscow also makes extensive use of conventional anti-personnel mines and improvised booby-traps to indiscriminately harm civilians. Dead bodies, the homes and vehicles of Ukrainian civilians and even children’s toys have been rigged up as lethal devices. Russia has laid mines remotely and mechanically, covering significant areas of farmland, with scant evidence that it has either marked minefields or warned civilians about their presence. Those minefields will leave a legacy long after the conflict ends.^[6]

The UN has estimated that clearing landmines and unexploded ordnance in Ukraine is expected to cost around US$34.6bn. It said the hazards posed a “considerable and growing” threat to the civilian population and “significantly impeded the country’s economic potential”.^[7] The UN also noted that Ukraine was experiencing a shortage of trained specialists to deal with the problem. Ihor Bezkaravainyi, Ukrainian deputy economy minister, has argued that “even if we collected all the sappers or trained people who can clear mines from all over the world and brought them to Ukraine, it would still not be enough”.

While Ukraine is a state party to the Ottawa Treaty, it was reported in November 2024 that it had received land mines from the US to help slow Russian advances further into its territory.^[8] Ukraine argued that because much of the civilian population had been evacuated from the affected areas, the tactical use of “non-persistent” mines, which become inert after a pre-set period, posed a minimal risk to civilians and was essential to stem Russia’s advance. Ukraine had also previously told the UN that due to Russia’s invasion of Crimea in 2014 it could not guarantee that it was abiding by the treaty.^[9]

1.3 Recent developments

The convention was opened for signature in Ottawa, Canada, in December 1997 and remained open at the UN headquarters in New York until its entry into force on 1 March 1999.^[10] As of 1 November 2024, the treaty had a total of 164 state parties, including the UK and Ukraine, with 33 states who had not joined, including Russia and the United States (a full list of the states party to the Ottawa Treaty as of 1 November 2024 is set out in the ICBL’s ‘Landmine monitor 2024’).

However, in a joint statement on 18 March 2025, the ministers of defence for Estonia, Latvia, Lithuania and Poland announced that they were withdrawing from the Ottawa Treaty.^[11] The countries said that since they had ratified the treaty, “the security situation in our region has fundamentally deteriorated”. It argued that:

Military threats to NATO member states bordering Russia and Belarus have significantly increased. In light of this unstable security environment—marked by Russia’s aggression and its ongoing threat to the Euro-Atlantic community—it is essential to evaluate all measures to strengthen our deterrence and defence capabilities.^[12]

The countries said that despite their withdrawal, they remained committed to international humanitarian law, including the protection of civilians in armed conflict. They also thanked their allies and partners for their understanding and support of the decision.

In December 2024, the Finnish government said it was also considering withdrawing from the Ottawa Treaty.^[13] Finland’s defence minister, Antti Hakkanen, said his country needed to re-evaluate the importance of such weapons for its defence and highlighted Russian tactics and its use of landmines in Ukraine.

1.4 Reaction to the Baltic States and Poland’s withdrawal

The UK government has said that it remains committed to the Ottawa Treaty and has no plans to leave.^[14] However, it has also given its support to the nations that have chosen to withdraw. A spokesperson for the Foreign, Commonwealth and Development Office said:

The UK remains unwavering in its commitment as a state party to the Ottawa Treaty, and we value the important role it plays in protecting civilians from harm. It is the sovereign right of these countries to make this decision. We will continue to engage these states on action they plan to take in order to minimise any impacts on our shared interests in humanitarian arms control and disarmament and to advance European security in the face of Russia’s illegal invasion of Ukraine.^[15]

Maris Andzans, director of the Centre for Geopolitical Studies in Riga, has described the decision to withdraw from the treaty as controversial but “logical when done as a group”.^[16] He argued the decision provides the ground to build a united defence line against Russia and Belarus. He also said it would send a strong signal that the Baltic states and Poland are very concerned and “ready to go beyond the current measures”. Tomasz Grzywaczewski from the Warsaw Institute think tank said that while the Ottawa Treaty had been effective, its viability had been threatened by Russia. He argued that the war in Ukraine had shown that despite their cruelty, landmines can be used to “protect your sovereignty effectively again aggression”. Domestically, a Policy Exchange research note, in part authored by Lord Verdirame, argued that the UK and its western European allies should consider their position under the Ottawa Treaty.^[17]

However, various non-governmental stakeholders have been critical of the Baltic States and Poland’s decision. For example, the International Committee of the Red Cross said it was “gravely concerned” by the decision.^[18] Its chief legal officer, Cordula Droege, argued that the move was a “deeply troubling step backwards”. Eva Maria Fischer, head of advocacy at Handicap International Germany, also said the decision was worrying and a threat to the convention. In addition, she argued that studies have shown that the weapons have limited military value.^[19]

2. Convention on Cluster Munitions

2.1 Overview

The Convention on Cluster Munitions prohibits under any circumstances the use, development, production, acquisition, stockpiling and transfer of cluster munitions, as well as the assistance or encouragement of anyone to engage in prohibited activities.^[20] The convention opened for signature in December 2008 and entered into force on 1 August 2010. It has 112 states parties and 12 signatories; however, this does not account for Lithuania, which has recently withdrawn from the convention.^[21] Ukraine, Russia, Poland, Latvia and Estonia as well as the United States and Finland are not states parties to the convention. However, the UK is a state party to the convention and the main tenets of the convention are found domestically in the Cluster Munitions (Prohibition) Act 2010.

The convention describes a cluster munition as a conventional munition that is designed to disperse or release explosive submunitions each weighing less than 20kg.^[22] The UN has said that many of these submunitions are often unreliable and fail to explode, effectively creating landmines.^[23] As a result, the use of such weapons can impact civilians during a conflict and long after it ends both physically and by creating barriers to socio-economic development.

2.2 Recent use of cluster munitions in Ukraine

The Cluster Munition Coalition, a global civil society coalition of hundreds of organisations, has said that the “most extensive use of cluster munitions in the world is seen in Ukraine”.^[24] In its ‘Cluster munition monitor 2024’, the coalition reported that Russia has used cluster munitions repeatedly since the first day of its full-scale invasion of Ukraine in February 2022. The coalition said that use of the weapons had killed and injured hundreds of civilians, damaged civilian infrastructure and contaminated agricultural land. It said that Ukraine had the highest number of annual casualties for the second consecutive year, and that since February 2022 over a thousand cluster munition casualties had been recorded in the country.

The coalition’s report also noted that Ukrainian forces had used cluster munitions, resulting in civilian casualties.^[25] It said that between July 2023 and April 2024 the then US president, Joe Biden, had approved five transfers of cluster munitions to Ukraine. The coalition argued that the actions of non-signatories may be influencing others. Both the US and Russia are not signatories to the convention.

2.3 Recent developments

In March 2025, Lithuania withdrew from the Convention on Cluster Munitions citing concerns about Russian aggression.^[26] The Lithuanian Ministry of National Defence said that Russia had become a “direct threat” to Lithuania and this change required it to “revisit provisions of the convention from the perspective of national security”.^[27]

2.4 Reaction to Lithuania’s withdrawal

The UK government has said that it regrets Lithuania’s decision to withdraw from the Convention on Cluster Munitions.^[28] In answer to a parliamentary written question on the subject, the government said it had frequently raised its concerns with the Lithuanian government alongside NATO allies. It also said that the decision was “another reminder of the damaging effects of Russia’s aggression and its impact on its neighbours”.

Other stakeholders have raised concerns about Lithuania’s decision. For example, the president of the 12th meeting of the states parties to the Convention on Cluster Munitions said that they “deeply regret” Lithuania’s notice of withdrawal.^[29] They highlighted that it was the first time any state had denounced a humanitarian disarmament treaty and said they were compelled to note that “this decision may have widespread implications indicative of an overall weakening of international humanitarian law”. In addition, the president’s statement said that the impact of recent use of cluster munitions in conflicts should be reinforcing the respect for the convention’s complete ban of such weapons. The Cluster Munition Coalition also published a statement in which it argued that Lithuania’s arguments in favour of withdrawal were “deeply flawed”:

Lithuania has never possessed or produced cluster munitions, so it would not be in [a] position to use them in the near term. Moreover, Ukraine’s freedom to use cluster munitions—it has never been party to the Convention on Cluster Munitions—did nothing to deter Russia’s invasion in 2022. In any case, it is difficult to believe that one outdated weapon system will deter a resolute aggressor. On the other hand, if Lithuania were to use cluster munitions on its own territory, there would be massive long-term costs for civilians living in contaminated areas.^[30]

The International Committee of the Red Cross said it “deeply regrets” Lithuania’s withdrawal, while Human Rights Watch was also critical of the decision.^[31]

However, there have been calls for more countries to exit the convention. An article published by the Centre for European Policy Analysis (CEPA) contained a call for European countries to withdraw from the convention arguing that it “amounts to a serious act of military self-harm”.^[32] The author of the article, Dan Rice (president of the American University Kyiv and co-president of Thayer Leadership at West Point), has argued that the weapons were effective on the battlefield and would be necessary to help defend some of the Baltic states in the event of an attempted Russian invasion. He recommended that all NATO member states withdraw from the Convention on Cluster Munitions. The Policy Exchange research note also called on the UK government to review its position under the convention and encourage western European partners to do the same. The authors (including Lord Verdirame) argued that:

We must act to provide timely and valuable diplomatic support for front-line allies exiting the treaties, and, more importantly, to show that we are ready to take the steps necessary to enhance our conventional deterrence at a time when, as a result of American disengagement and European disarmament, decisive action is required. The UK could then work with Ukraine, Poland, the Balts, and Finland to increase European military stockpiles of both critical weapons [anti-personnel mines and cluster munitions].^[33]

3. Read more

• House of Lords Library, ‘Recent US and UK government policy on Ukraine’, 12 March 2025
• House of Commons Library, ‘UK government support for the explosive ordnance disposal community’, 9 December 2024
• Human Rights Watch, ‘Landmine use in Ukraine’, June 2023

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Cover image from Flickr.