Military power of NATO & British–Polish–Ukrainian trilateral pact

The North Atlantic Treaty Organization (North Atlantic Alliance) is an intergovernmental military alliance which was signed in Washington on 4 April 1949. NATO is a system of collective security: its independent member states agree to defend each other against attacks by others countries. NATO's main headquarters are located in Brussels. The following twelve states signed the treaty and became the founding members: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, Netherlands, Norway, Portugal, United Kingdom and United States. The following states joined the treaty after 1949: Greece, Germany, Turkey and Spain. Members who joined after the dissolution of the Soviet Union: Czech Republic, Hungary, Poland, Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, Slovenia, Albania, Croatia, Montenegro and North Macedonia.

Before and during the 2022 Russian invasion of Ukraine, several NATO countries sent army to reinforce the alliance's eastern flank. Alliance had deployed 40,000 troops along its 2,500 kilometres long Eastern flank to deter possible Russian aggression. On 5 July the North Atlantic Alliance members signed off on the accession protocols for Sweden and Finland and formally approved the decisions of the NATO summit.

Finland joined the alliance on 4 April 2023.

The British–Polish–Ukrainian trilateral pact is an agreement between Poland, Ukraine and the United Kingdom. The pact was signed on February 17 in Kyiv. The pact serves to improve cyber and energy security. This alliance is a part of Ukraine's broader strategy to form small alliances like Ukraine–Poland–Lithuania, Ukraine–Georgia–Moldova and Ukraine–Turkey. As part of the pact, arms deliveries are carried out by Great Britain and Poland to Ukraine.