As a share of gross domestic product (GDP), Ukraine spent more on its military than any other country in 2023, reaching 37 percent of the country's GDP. The high figure is due to the country being invaded by Russia in February 2022. Algeria and Saudi Arabia followed behind.Leading military spending countriesIn gross terms, the countries with the highest military spending are the United States, China, and Russia. However, these are countries with large populations and GDPs, and smaller countries usually cannot compete alone, regardless of how much they invest. For this reason, they form alliances such as the North Atlantic Treaty Organization (NATO). NATO countries aim to pool two percent of their GDP towards their own militaries and to aid each other in case of war. Regional differencesThe past decade has seen an increase in global military spending. This has not been distributed evenly. That period saw large positive changes in military spending from several Asian countries, including a large increase from China. While this does not reflect the number of active conflicts, it reflects growing tensions in global affairs.