Swedish neutrality
Sweden had a policy of neutrality in armed conflicts from the early 19th century, until 2009, when it entered into various mutual defence treaties with the European Union (EU), and other Nordic countries. The policy originated largely as a result of Sweden's involvement in the Napoleonic Wars, during which over a third of the country's territory was lost in the Finnish War (1808–1809), including the traumatic loss of Finland to Russia, which it remained part of until Finland gained independence in 1917.