Russia’s aggression against Ukraine and unfriendly behaviour against other countries of the region led to a change in the perception of the Russian threat in many countries across Eastern Europe.

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Russia’s aggression against Ukraine and unfriendly behaviour against other countries of the region led to a change in the perception of the Russian threat in many countries across Eastern Europe. This was reflected in new versions of national security strategies in most states of the region. The Eastern flank countries are increasingly aware of the need for solidarity, as reflected in the establishment of the Bucharest Nine (B9). Notably, B9 focuses strongly on developments in Ukraine and Russia’s aggression, including through repeated and unconditional support of Ukraine’s territorial integrity and sovereignty. Kyiv has an open window of opportunities to join B9. This would strengthen this format and provide added value to all its participants.

The Bucharest Nine is a security formation of nine NATO eastern flank member-states. These include Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, and Slovakia. Launched in November 2015, in Bucharest (Romania) upon the initiative of Romania and Poland, its members were brought together by the common geopolitical burden of being part of the “Soviet bloc”, i.e. the Warsaw Pact, the Council for Mutual Economic Assistance and the Soviet Union. The common burden now is the fear of threats coming from Russki Mir regardless of NATO membership, the expansion of Russia’s political control and domination, its policy of imperial revanchism and the subsequent geopolitical and cultural takeover. It is only natural in this context that the Russian aggression against Ukraine aggravated their concerns, pushing them to join efforts to avoid catastrophic scenarios. 

B9 states do not just show leadership in accomplishing NATO’s defence goals. Russia’s military aggression against Ukraine and the commitment to military spending at 2% of the GDP undertaken by NATO member-states encouraged them to actually boost their spending on the security sector. Military spending of Bulgaria, Romania, Latvia, and Lithuania grew 18-24% throughout 2018 compared to 2017. This is comparable to the 21% growth of the military spending of Ukraine at war over the same period. Out of the B9 states, Bulgaria made it over the 2% threshold in 2019 with 3.25%, Estonia with 2.14%, Romania with 2.04%, Lithuania with 2.04%, Latvia with 2.01%, and Poland with 2.00%. Slovakia with 1.74%, Hungary with 1.21%, and the Czech Republic with 1.19% failed to reach the threshold. In 2020, however, Slovakia hit the 2% mark too.

In addition to that, B9 states draw the attention of NATO to the challenges on its eastern border and engage in designing multilateral instruments for deterring Moscow.


Foreign Ministers of the founding countries met for the first time after establishing B9 in November 2016. NATO Deputy Secretary-General Rose Gottemoeller attended the meeting. At that meeting, the founders outlined the fundamentals of B9. The Joint Declaration listed these fundamentals as recognition of the fact that Russia’s actions undermined European security architecture and condemnation of Russia’s aggressive actions against Ukraine and violation of international law, including through the occupation of Crimea. Also, the diplomats highlighted their support for Ukraine’s sovereignty and its undeniable right to independently decide on its future and conduct its foreign policy without external interference.

To some extent, B9 members projected their own concerns about Moscow’s international voluntarism in their reference to Ukraine. The 2017 Declaration similarly focused on Ukraine and Russia’s aggressive conduct. As they called for the implementation of the Minsk Agreements, B9 member-states highlighted the need to stop aggressive actions and withdraw troops from the territory of Ukraine. Notably, the 2017 Declaration was approved after the Verkhovna Rada passed the Law on Education where Art. 7 on the language of education for ethnic minorities triggered an escalation in relations with Hungary and cooling in relations with Romania. Still, neither Bucharest nor Budapest blocked the B9 Joint Declaration. 

In 2018, Heads of States and Governments of B9 states confirmed in a Joint Declaration their commitment to the policy of deterrence and defence from Russia, emphasised their support for Ukraine’s European and Euro-Atlantic aspirations, and expressed support for the territorial integrity of Georgia and Moldova. At the B9 summit in February 2019, they adopted another declaration that mentioned the ongoing conflict in Eastern Ukraine and the growing tensions in the Sea of Azov and the Black Sea. B9 states consistently supported Ukraine’s sovereignty and territorial integrity within its internationally recognised borders.

With the COVID-19 lockdown restrictions, B9 founding countries met just once in 2020-2021. Presidents of Poland and Romania, Andrzej Duda and Klaus Iohannis, held a mixed-format summit in Bucharest on May 10, 2021, joined by the leaders of seven B9 member-states, US President Joe Biden and NATO Secretary-General Jens Stoltenberg. The US participation reflected its interest in strengthening cooperation with Central and Eastern European countries, and the participation of the Secretary-General of NATO illustrated the interest in developing the Euro-Atlantic partnership. The US expressed its support and commitment to strengthening transatlantic relations. The US President assured B9 leaders of the aspiration for closer cooperation among NATO allies in Eastern Europe and highlighted the importance of strengthening NATO capacity in the Baltic and the Black Sea regions. To some extent, this top-level representation of the US reflected the efficiency of the B9 strategy: the concerns of countries in the region were heard in Washington, so chances for security of the region to be treated as a priority have been preserved.

Another proof of B9 importance for NATO and Ukraine comes from the conversation US President Joe Biden had with B9 leaders on December 9, 2021, shortly after his talks with Russia’s President Vladimir Putin. During it, the B9 and US leaders discussed the build-up of the Russian troops on Ukraine’s borders, and the US President assured them that the US remained committed to the idea of de-escalation through deterrence, defence, and dialogue. 

Moreover, the countries shifted from a consensus definition of Russia as a threat to discussing specific manifestations of that threat and ways to counter it. The 2021 summit agenda reflected and condemned past and possible “acts of diversion” by Russia on the territory of NATO member-states, referring primarily to explosions at ammunition warehouses in the Czech Republic in 2014. In May 2021, Czech Finance Minister Alena Schillerová spoke about this, highlighting her country’s intent to demand reimbursement of the losses caused by the explosions from Russia. 

At the 2021 Summit, B9 leaders once again expressed support for the independence, sovereignty and territorial integrity of Ukraine in its internationally recognised borders and assured of further support for its EU and NATO aspirations. This narrative is worth mentioning as it reflects the rejection of Russia’s narratives on what it calls spheres of influence, buffer zones, and bans on NATO expansion sought by Moscow. In their statement, B9 leaders said that Russia’s aggressive actions, including in the Black Sea region and along Ukraine’s land border, threatened Euro-Atlantic security and challenged international order. This statement should be seen as a notable and positive step for Kyiv and the development of a potential B9+ format as a formal manifestation of support for eastern neighbours of the B9 states, and as coordination of defence and security efforts among them.


Despite examples of more extensive cooperation with NATO, the established regional partnership formats, such as bilateral Ukraine-Romania cooperation in regional security and the annual Riverine security exercise in the Danube, facilitate the development of the B9+ format potential. The September 2019 exerciseі lasted several days, engaging Romania’s Navy and Coast Guard and Ukraine’s Navy and State Border Service Sea Guard. In the Danube manoeuvres, the Ukrainian and Romanian military worked on the key elements of security in straits and river sectors. This format of cooperation continued in the following years. In 2020, the exercise started in Ukrainian Izmail. It focused on the joint action of multinational tactical boat groups in the Danube basin. In addition to that, Riverine helps evaluate the interoperability of Ukraine’s Navy and sea border guard with similar units in Romania as a NATO member-state. 2021 was no exception. 

The level of organisation shows that this exercise has especially important political and security significance for both parties. It has become regular and annual, led by representatives of the command of Ukraine’s and Romania’s armed forces. Riverine takes place in the Black Sea subregion of the Danube. According to Rear Admiral Oleksiy Neizhpapa, Commander of the Ukrainian Navy, “The 2021 Riverine drills prove the friendship and partnership of our countries and understanding of the importance of ensuring security in river sectors and straits. They offered a good opportunity to improve interoperability and capabilities and to exercise international standards of interaction.” Rear Admiral Mihai Panait, Commander of the Romanian Navy, stressed that “modern challenges and threats, such as terrorism, illegal migration or the pandemic, force us to act together. 2021 Riverine becomes a necessary tool of joint training of our Navies. Starting with a small-scale exercise, we are expanding both the number and forces of the participants and the complexity of the drills.”

The format of the drills allows the involvement of the Navies and units of Ukraine’s State Border Service Sea Guard and Romania’s Border Police, the force entities of a NATO member-state. This allows Ukrainian entities to improve interoperability with NATO member-states and partners and build up the respective capabilities. In the drills, tactical groups from Ukraine and Romania work to strengthen regional security. 

The participation of the Lithuanian-Polish-Ukrainian Brigade – associated politically with the Lublin Triangle, a regional initiative by Poland, Lithuania, and Ukraine – in a number of military-political initiatives in recent years can/should also be viewed in the context of B9+ development prospects. The 2019 Rapid Trident multinational exercises in September 2019 focused on tabletop and field exercises of the Brigade units. Over February 17-21, 2020, the Lithuanian-Polish-Ukrainian Brigade conducted Brave Band, the tabletop exercises without involving core forces and means. The Three Swords 2021 exercise in July 2021 engaged nearly 1.500 troops from Ukraine, Poland, and Lithuania, aimed at improving and deepening the partnership and military cooperation of the countries involved.

Tisa Multinational Engineering Battalion with Romania, Slovakia, and Hungary is another platform for working on interoperability with NATO member-states and members of B9. The Light Avalanche annual exercise focuses on evacuating people from dangerous and threatening regions, providing essentials to the affected population, riverbank stabilisation, and reinforcement of hydro-technical facilities, road cleaning and reconstruction of damaged infrastructure. The exercise in mid-September 2019 took place in Hungary, as host countries for the Light Avalanche rotate on an annual basis. In the next step of developing and fine-tuning its skills, the staff of the Tisa battalion moved to joint command exercises involving the military in various formats. Given the notable accomplishments of Tisa and its significance in strengthening regional security cooperation, Ukraine’s Verkhovna Rada has recently passed the Law on Ratification of the Protocol of Agreement Between the Cabinet of Ministers of Ukraine and the Government of Hungary, the Government of Romania and the Government of Slovakia on Establishing a Multinational Engineering Battalion. This expanded the area of its activities beyond the Tisa (Tisza) basin, adding help to the local civilian population and dealing with natural disasters in the basins of the Tisa and Danube rivers to its portfolio.

Most of the current military exercises in Central and Eastern Europe contribute similarly to the development of security and defence cooperation within B9 and potentially B9+, a hypothetical format that could engage Ukraine in some manner. Listed below are the ones where Ukraine participated, including in 2021: 

  • Riverine tactical military exercises (with the participation of Romania and Ukraine);
  • Light Avalanche tabletop military exercises (with the participation of Hungary, Slovakia, Romania, and Ukraine, based on the Tisa Multinational Engineering Battalion); 
  • Dynamic Front tactical exercises (with the participation of Poland and Ukraine); 
  • Combined Resolve tactical military exercises (with the participation of Lithuania, Poland, Romania, and Ukraine); 
  • Agile Spirit tactical military exercises (with the participation of Poland, Romania, Latvia, Estonia, Lithuania, and Ukraine);
  • Dive tactical navy and salvage exercises (with the participation of Romania, Bulgaria, and Ukraine);  
  • Saber Guardian tabletop exercises (with the participation of Poland, Hungary, Bulgaria, and Ukraine); 
  • Trojan Footprint tabletop exercises (with the participation of Romania, Hungary, Bulgaria, and Ukraine); 
  • Saber Junction tabletop exercise (with the participation of Bulgaria, Hungary, Lithuania, Poland, Romania, and Ukraine);
  • Maple Arch tabletop exercise (with the participation of Lithuania, Bulgaria, Poland, and Ukraine); 
  • Iron Wolf tactical exercise (with the participation of Lithuania, Latvia, Czech Republic, Poland, and Ukraine); 
  • Nighthawk tabletop exercise (with the participation of the Czech Republic, Estonia, Lithuania, Poland, and Ukraine);
  • Beyond Horizon tactical military exercises (with the participation of Bulgarian, Romania, and Ukraine); 
  • CWIX 2021 training for technical interoperability in telecommunication technology and cybersecurity (with the participation of Poland and Ukraine). 

Some exercises worth noting took place in Ukraine: 

  • Sea Breeze 2021 navy exercises (with the participation of Bulgaria, Romania, Estonia, Latvia, Lithuania, and Poland); 
  • Rapid Trident exercises (with the participation of Bulgaria and Poland); 
  • Joint Efforts military tactical exercises (with the participation of Latvia, Lithuania, Poland, Slovakia, Romania, and Hungary); 
  • Cossack Mace military exercises (with the participation of Lithuania); 
  • Three Swords military exercises (with the participation of Poland and Lithuania); and 
  • Silver Sabre military exercises (with the participation of Poland). 

These exercises, the various tasks they focus on, the wide range of participants they engage, and their intensity and efficiency prove that Russia’s aggressive actions in the international arena have pushed many B9 members to revise their approach to security and the challenges emanating from Moscow in recent years. Amendments in National Security Strategies of the B9 member-states offer another illustration of this revision. 


Bulgaria updated its 2011 National Security Strategy in 2018. The changes focused on the hybrid nature of threats. The novelties were primarily driven by Russia’s occupation and attempted annexation of Ukrainian Crimea in 2014 that revealed Russia’s nihilism of international law, even where Moscow was a signatory and guarantor of upholding it. It is also worth adding that the growing hybrid threat from Moscow is mentioned in the Defence Strategy of Bulgaria in the context of ensuring stability, security, and development of the Black Sea region.

Estonia’s 2017 National Security Strategy focuses on the threats coming from Russia too. It says that Russia’s actions are increasingly threatening and aggressive in the sphere of European security. Moscow puts the military element in the key role in its pursuit of the geopolitical weight it had in the past. The build-up of its military units, including along Estonia’s borders, creates a threat and destabilisation in the Baltic region. In its National Security Strategy, Estonia notes the efficiency of sanctions against Russia and the need to further increase them.

Also, Estonia looks at the issue of European unity. Among other things, its National Security Strategy notes that EU member-states should be more consolidated and act in a united front against Russia’s voluntarist policies. Otherwise, weakness and the lack of unity will increasingly encourage Russia’s aggressive policy. The Strategy mentions that Tallinn will increasingly invest efforts into forging more unity in the EU and NATO to counter Russia’s aggressive politics. 

Latvia’s National Security Strategy of 2020 pays a lot of attention to Ukraine in the context of Russia’s aggression. Given Russia’s brutal violation of international law and military aggression against Ukraine, Latvian partners include measures to prevent elements of a hybrid war scenario against their national security in their security documents. Riga looks at the mechanisms Russia used to launch and conduct its hybrid aggression against Ukraine in detail. A particular focus of Latvia’s Strategy is on the close cooperation of all public institutions, primarily defence and law enforcement agencies, to prevent any internal destabilisation and ensure critical state resilience.

In its 2017 fundamental security document, Lithuania also focuses heavily on Russia’s aggressive actions. Among other things, Lithuanian military and political leadership calls and sees as threatening the placement of Russian military forces and means along its border, including with Kaliningrad Oblast, the adjacent Russian enclave. Also, the strategy notes that Russia’s ability to use a mix of military, economic, energy, and information tools against its neighbours is a threat to Lithuania’s national security and security of the entire Euro-Atlantic community, primarily political and institutional. Lithuania sees that Russia will use this hybrid aggressive approach in the current period and the future. In their strategy, Lithuanian partners call on Russia to comply with the norms and principles of international law, and fulfil its international commitments in complying with and implementing the Minsk Agreements.

In its 2020 National Security Strategy, Poland refers to the policy and nature of Russia’s behaviour in Central and Eastern Europe, primarily towards its neighbours, as neo-imperial and views Russia as the greatest systemic threat. The Strategy also notes that Moscow seeks to accomplish its neo-imperial goals with military force. As examples, Polish officials list the aggression against Georgia with the occupation of Abkhazia and South Ossetia, and Ukraine with the occupation of Crimea and some parts of Donetsk and Luhansk oblasts. The Strategy highlights that these actions by Russia undermine the principles of international law and the European security system. Similarly to Lithuania, Poland sees Moscow’s build-up of military forces and means along the Polish border, including the adjacent Kaliningrad Oblast, as a threat. 

Also, it focuses on non-military actions, including disinformation, propaganda, and cyber threats. The Strategy notes that the elements used by Russia, including direct force and hybrid pressure, continuously undermine international law and world order and aim at expanding Russia’s current sphere of geopolitical control and influence. It notes that energy security is an integral component of Poland’s general security. This is especially relevant with the completion of Nord Stream 2, a pipeline that is a source of threat for Poland and the EU in general. Poland’s National Security Strategy points to the fact that fuels and their supply could be used for political pressure against the countries that rely on Russian gas, among others, if the pipeline is launched. 

In its strategic documents from 2020, Romania highlights Russia’s unacceptable and partly aggressive conduct in the international arena and in the Black Sea region where serious militarisation is taking place. Russia’s build-up of its force component, its aggressive actions, especially in recent years, and improvement of hybrid action do not leave Romania with options, other than continued strengthening of collective security in the Black Sea that includes reliance on its NATO and EU allies and Eastern Partnership countries.

Bucharest sees B9 and Three Seas Initiatives as meaningful instruments. These regional initiatives aim to strengthen the security environment, reinforce the capabilities of the countries in NATO’s eastern flank, and increase their contribution to the Black Sea security. Regional cooperation in this area increased significantly against the backdrop of Russia’s aggressive actions against Ukraine, Georgia, and Moldova. Russia-backed military actions in the East and South are an additional threat for Romania.

Slovakia updated its Security Strategy in 2021. These updates consider the new reality and the Russian threat. Among other things, it mentions conflicts in Georgia and Eastern Ukraine triggered by Russia’s aggressive actions, and illegal occupation of Crimea, which Slovakia interprets as a severe violation of international law. The Strategy states that Slovakia believes Russia’s confrontational approach in the military and security domains to be a serious challenge that Bratislava cannot overlook. Therefore, Slovakia will support sanctions against Russia if necessary. Moreover, Bratislava openly supports the Euro-Atlantic ambitions and aspirations of Georgia, Ukraine, and Western Balkan states. Finally, Bratislava sees the termination of Russia’s war against Ukraine, including returning of all occupied territory to Ukraine, as a key objective of its own security. 

Unlike its B9 partners, Hungary is quite tolerant about Moscow’s policy in Central and Eastern Europe and its security policy overall in the 2020 Government Resolution – its recent strategic document. It describes Russia as one of the key players in the global and regional security sectors. It states that NATO and Russia should work closer in the practical military and civilian domains. The document highlights the need to develop political dialogue in order to avoid a possible escalation of the conflict between NATO and Russia. Obviously, this formal stance of Hungary is dissonant with the positions of other B9 states and counters its purpose and goals. 

This political paradox may have the following rationale: the de facto participation of Budapest in B9 signals that it shares the purpose and goals of these regional initiatives and actually recognises the threats generated by the revanchism of Russia’s current policy in Europe. After all, the open letter of Hungary’s Prime Minister Viktor Orban to then German Chancellor Angela Merkel published in December 2021 points to this assessment. It mentions the Ukraine-Russia war and acknowledges the need to counter such destructive and undermining policy of Moscow, albeit Budapest is reluctant to codify this because of the diplomatic game and specific economic interests. 

Moreover, the Czech National Security Strategy dated 2015 does not mention Ukraine or Russia, while the 2017 Defence Strategy only mentions the violation of the “territorial integrity of neighbouring countries” by Russia. However, these documents will likely to be revised after the new Czech government is formed in 2022. 

This is relevant as the Czech Republic has been a target of destabilisation attempts by Russia. As mentioned above, one incident was the explosion of ammunition warehouses in 2014. This ammunition was supposed to be sent to Ukraine in support of its defence. In April 2021, the Czech Republic expelled a large group of Russian diplomats who were recognised as Russian agents when Moscow’s involvement in the explosion incident was confirmed. Later, an agent network of Russian hackers was discovered in the Czech Republic. They committed serious cyber-attacks in the Czech Republic and the neighbouring states. In another notorious incident, the Czech security services prevented an attempted poisoning of Prague Mayor Zdeněk Hřib and Ondřej Kolář, head of a Prague district, in revenge for removing the monument to Soviet General Ivan Konev. These and other hostile actions of Russia against the Czech Republic resulted in a serious deterioration of bilateral Prague-Moscow relations, diplomatic scandals, and demarches. 

Czech political discourse and politics offer harsh conclusions on the need to strengthen protection from Russia’s undermining and aggressive activities domestically and within the EU. Such political sentiments cannot be overlooked in the Czech legislation. Therefore, the respective changes should be expected in a range of laws and guiding strategic documents in the near future. 

As a summary of all the above, international positioning, conduct and shaping of a common security policy by B9 states in the context of the Russian threat to the stability, development, and security of Central and Eastern Europe prove that the establishment of B9 was a timely strategic response of CEE countries that are part of the EU and NATO to the Russian aggression against Ukraine, including the occupation and attempted illegal annexation of Crimea, and the occupation of parts of Donetsk and Luhansk oblasts. The analysis of political statements and decisions by heads of states in the region proves that B9 capitals are convinced that the Russian revanchism is not just a bluff by Moscow, but the asset on which the legitimacy and authority of its government, its political continuity, and vision of its historical perspective rely, using the tools of propaganda. Therefore, Moscow hardly hides the fact that it will not limit its appetite after swallowing Ukraine. Instead, it will further destabilise vulnerable subregions of CEE. Russia’s awareness of this approach crystalised after the beginning of Russia’s aggression against Ukraine, as described in our previous research. 


Content analysis of the statements, documents, and steps by B9 leaders signals that B9 countries are aware of stronger European and Euro-Atlantic solidarity, cooperation with the US, increased defence spending and justified necessity to provide comprehensive support to Ukraine as the key predicaments for ensuring stability, security, and development in the region. In this favourable context, Ukraine should intensify relations with CEE countries within B9 and open a window of additional opportunities for setting up B9+. This is of special interest in the situation where Ukraine is in the status of a partner-state rather than a NATO member-state. 

Therefore, Ukraine is in a position to initiate formalised mutual assistance and solidarity with B9 in countering Russia’s military expansion. This would help boost the current B9 format into a full-fledged B9+Ukraine or B10. Supported by Ukraine’s allies, primarily the US, this format would decrease risks in designing solidarity approaches to the policy of deterring Russia and guarantee security and defence resilience of countries in NATO’s eastern flank.  

Ukraine should focus on the following areas to accomplish these goals: 

  • It seems advisable to start regular Conferences of Defence Ministers of B9+Ukraine to share information, shape a joint vision and joint responses on the security challenges provoked by Russia in the region; 
  • Based on the available solidarity and mutual understanding among B9 states and Ukraine, to invest diplomatic and political efforts into forming a B9 countries club of support for Ukraine joining NATO. With this, Kyiv has a chance to strengthen the loyalty of Washington and weaken the scepticism of Berlin in this matter;
  • To initiate the involvement of military specialists from B9 states to support the Armed Forces of Ukraine in overcoming the existing gaps and strengthening the Ukrainian Army capabilities. Ukraine can initiate sending more advisors of B9 countries to work at NATO Representation to Ukraine and for some advisory initiatives; 
  • To contribute to shaping a security identity within B9 that would reflect the understanding of own responsibility for supporting stability and ensuring regional security, and recognising the need to expand NATO’s responsibility zone beyond its borders to the countries that share the values of a free and the rule of law society and comply with the criteria of the democratic world while also facing unjustified aggression from third parties;
  • A joint summit of the Visegrad Four and the Lublin Triangle with other NATO member-states, including Turkey and the EU, could catalyse the shaping of B9+. It is also possible to consider inviting Georgia to such a summit; 
  • The B9 and Ukrainian expert community should initiate a B9+ Expert Forum that could provide analytical support in evaluating regional threats, the prospects of Ukraine’s integration with NATO, and efforts to increase compatibility and shape the joint strategic vision of cooperation.