The topic is especially relevant today because it highlights how the EU and the US are supporting Ukraine in its fight against russian military aggression through their foreign policies.

For the past three years, Ukraine has been undergoing one of the most challenging periods in the history of its statehood, marked by the consolidation of its independence and the affirmation of its national, state, and territorial sovereignty through resistance to the unlawful actions of a hostile state.

Since 24 February 2022, the Ukrainian state and its society have been taking all possible measures aimed at the protection of the nation. A significant portion of Ukrainian citizens risk their lives daily in the performance of socially vital duties; Ukrainian men—and women as well—endanger their lives and health while participating in active combat operations. Both public and private sectors continue their planned activities despite the tangible threat to safety, particularly in regions where hostilities are ongoing. Emergency response services, including the National Police, Ambulance Service, and the State Emergency Service, are fully mobilized to ensure the rescue and protection of the civilian population.

Each year, Ukrainian public authorities enact a wide array of legislative measures to support the continuity of life during wartime, including but not limited to: the development and implementation of state assistance programs for internally displaced persons and others affected by the consequences of military operations; the delivery of specialized emergency training programs for healthcare professionals; and the elaboration of reconstruction plans for destroyed infrastructure.

Nevertheless, despite these comprehensive efforts, Ukraine cannot mount a full-scale and sustained resistance against the aggressor without the assistance of its developed partner states. Securing victory over the aggressor and achieving legal recognition of the russian federation’s commission of international crimes on Ukrainian territory requires, as a matter of necessity, the engagement and support of as many powerful nations as possible.

When analyzing the assistance provided by foreign partner states from an international legal perspective, it is important to emphasize that, under conditions of russia’s full-scale aggression against Ukraine, the conclusion of bilateral and multilateral international treaties by Ukraine concerning the provision of legal assistance acquires particular significance.

On the one hand, the onset of war has severely constrained the possibilities for diplomatic cooperation and the conduct of comprehensive negotiations. On the other hand, the very act of concluding and complying with international treaties serves as a powerful instrument for protecting Ukraine’s national interests, its state sovereignty, and its territorial integrity.

Furthermore, the conclusion of international agreements by influential global actors aimed at supporting Ukraine—as a state facing existential threat—constitutes not only a meaningful contribution to Ukraine’s defense, but also serves to enhance the international reputation of such states. These actions play a critical role in the maintenance of international peace and security and in countering war crimes.

  When examining international legal support enshrined in official documents, it is essential to underscore that international treaties concluded by Ukraine during the period of martial law explicitly affirm Ukraine’s status as a sovereign and independent state engaged in a just defensive war against an aggressor. The conclusion of agreements on economic, military, and humanitarian assistance plays a decisive role in ensuring the resilience of the Ukrainian state under wartime conditions.

Among the most critical of Ukraine’s agreements with partner states are international treaties of a security-oriented nature—those aimed at guaranteeing Ukraine’s national security. These treaties encompass provisions for military support, including the supply of weapons, equipment, and other defense-related materiel; training and capacity-building programs for Ukrainian military personnel; the exchange of intelligence; and joint military exercises.

In addition, these treaties provide for significant economic assistance from powerful partner states—such as financial aid to stabilize Ukraine’s economy; the creation and management of recovery funds for infrastructure destroyed during hostilities; investment in economic and social reforms to enhance the efficiency of public governance; and support for Ukraine’s integration into the European community. Moreover, humanitarian assistance—comprising medical, material, and other forms of aid for populations affected by active hostilities—is a key component of such agreements.

A prime example of successful cooperation is the Agreement on Security Cooperation and Long-Term Support between Ukraine and the Kingdom of Belgium. This agreement provides that Belgium will allocate no less than €977 million in military assistance to Ukraine in 2024. Furthermore, it contains a guarantee by the Belgian authorities to continue supporting Ukraine throughout the ten-year duration of the agreement. Notably, Belgium has also committed to delivering 30 F-16 fighter jets to Ukraine by 2028. The agreement further stipulates Belgium’s obligation to provide timely security assistance, including advanced military equipment and weapons tailored to Ukraine’s operational needs, as well as support in conducting military training exercises. 

A similar treaty was concluded between Ukraine and the Federal Republic of Germany—the Agreement on Security Cooperation and Long-Term Support, signed on 16 February 2024. Under the terms of this agreement, the Federal Republic of Germany undertakes to provide Ukraine with all possible and maximum support within its capacity, aimed at restoring Ukraine’s territorial integrity as recognized by the Constitution of Ukraine and by international treaties ratified by Ukraine. Given Germany’s contributions since the beginning of the full-scale invasion, it is important to note that the Federal Republic of Germany remains one of the largest suppliers of military assistance to Ukraine and intends to provide sustained, long-term military support to the Armed Forces of Ukraine. This assistance is directed toward the full restoration of Ukraine’s territory and the reestablishment of its internationally recognized borders as of 1991, as expressly stated in the document.

When considering military assistance provided to Ukraine by European Union member states, special attention should also be given to the Agreement on Security Cooperation between Ukraine and the Republic of Poland, signed on 8 July 2024. The purpose of this agreement is to support Ukraine’s self-defence in response to ongoing russian aggression, through a series of joint measures undertaken by both countries. These measures include intelligence sharing; cooperation in the defense industry; training of Ukrainian military personnel; joint military exercises; ensuring cybersecurity; border defense; and disaster response operations. A notable feature of this agreement is the requirement for both parties to engage in consultations on Ukraine’s specific military needs. The agreement does not provide for the deployment of Polish troops on Ukrainian territory.

In turning to support from the United States, it is important to highlight the Bilateral Security Agreement between Ukraine and the United States of America, concluded on 13 June 2024. Legally, this is an international treaty between Ukraine and the United States that establishes security guarantees for Ukraine and sets out a comprehensive framework for long-term U.S. assistance. This assistance includes material, training, advisory, technical, intelligence, security, defense-industrial, and institutional support, among others.

Given that each European Union country is not only a sovereign and independent state but also a member of a powerful supranational political union, it is essential to note the Joint Security Commitments between Ukraine and the European Union, formalized in an agreement signed on the sidelines of the EU Leaders’ Summit on 27 June 2024. What distinguishes this agreement is the collective, long-term commitment made by all 27 EU member states. These commitments encompass extensive support for Ukraine in all key areas—military, financial, humanitarian, and political—throughout a ten-year period from the date of signature. A particularly significant provision of this agreement is the enshrinement of the EU’s commitment to support Ukraine until its accession to the Union, as well as the bloc’s readiness to assist Ukraine on its path toward EU membership.

Emphasizing the necessity of U.S. military support for Ukraine, President Joe Biden stated that such assistance is not only an investment in Ukraine’s security, but also in European and American security. “By sending Ukraine equipment from our own stockpiles, we will replenish these supplies with newly produced goods made by American companies here in the United States,” the President noted. He added: “Patriot missiles are made in Arizona, Javelins in Alabama, artillery shells in Pennsylvania and Texas. In other words, we are helping Ukraine while at the same time investing in our own industrial base, strengthening our national security, and supporting jobs in nearly 40 states across America.”

Biden also stressed that aid to Kyiv serves the interests of both the United States and NATO, noting that “the next step for russian forces could be a direct attack on a NATO ally,” which would trigger the application of Article 5 of the NATO Charter on collective defense.

Since the shift in U.S. leadership in 2025, the nature of American support for Ukraine has become more uncertain and subject to political fluctuations. President Trump introduced a temporary pause on military assistance, including halting shipments of weapons and equipment that had already been approved by Congress. This move surprised many allies and raised concerns about the continuity of aid critical to Ukraine’s defense efforts.

Beyond the pause, the Trump administration signaled a willingness to reassess foreign aid priorities broadly, often linking support to conditions such as economic or resource concessions, which complicated diplomatic relations with Kyiv. For example, there were proposals suggesting that the United States could seek access to Ukrainian mineral resources as part of future aid agreements—an idea that was firmly rejected by the Ukrainian government. While Congress and parts of the US political establishment have acted to counterbalance these shifts by passing substantial bipartisan aid packages, including multi-billion dollar funding bills to sustain military and humanitarian support, the overall picture reflects a more fragmented and unpredictable policy environment.

This uncertainty has implications beyond Ukraine, as it challenges the consistency of American security commitments and raises questions about the reliability of U.S. leadership in global conflicts. Allies in Europe and around the world watch closely, knowing that sustained political will and unified action are essential to supporting Ukraine effectively against ongoing russian aggression. The situation highlights the broader reality that international security depends not only on formal agreements but also on the stability and priorities of the governments that uphold them.

In summary, international support for Ukraine remains strong in general, with important contributions from the United States, the European Union, and individual allied countries. States such as Germany, Belgium, and Poland have formalized their commitments through security agreements. These include military aid, training programs, and promises to provide advanced weaponry. The European Union has also pledged a unified long-term response through the Joint Security Commitments, which include support in defense, finance, humanitarian aid, and politics for the next ten years.

International agreements, especially those that are not legally binding, rely entirely on the political will of the parties involved. This is not a new issue. In 1994, Ukraine gave up its nuclear weapons under the Budapest Memorandum in exchange for security assurances from countries including russia. Those promises were broken when russia invaded Ukraine.

Ukraine’s ability to defend itself and recover from the devastation of war depends on more than just signed agreements. It requires constant political engagement, practical support, and a clear understanding that defending Ukraine is not only about one country’s future, but about the stability and values of the wider international community.