Military alliances involving Bulgaria

The North Atlantic Treaty Organization (NATO) is an intergovernmental military alliance between 32 member states—30 in Europe and two in North America. Founded in the aftermath of World War II, NATO was established with the signing of the North Atlantic Treaty in 1949. The organization serves as a system of collective security, whereby its independent member states agree to mutual defence in response to an attack by any outside party. This is enshrined in Article 5 of the treaty, which states that an armed attack against one member shall be considered an attack against them all.

European Eastern Military Alliance (1954 – 1991)

military coalition in World War I

pact between Nazi Germany and Japan prior to World War II

treaty establishing the Axis Powers of World War Two

1915 treaty between Bulgaria and the Ottoman Empire

1914 alliance between the Ottoman Empire and Bulgaria

Treaty between Germany and Bulgaria