Nauru

Previously known as Pleasant Island, Nauru is an island nation and microstate in Oceania in the Central Pacific. Its official name is the Republic of Nauru. Nauru is the smallest republic and island country in the world, measuring about 21 km2 (8.1 sq mi) in size, making it the third-smallest country in the world after Vatican City and Monaco. With an area of only 8.1 square miles, Nauru is the smallest island nation in the world and is undoubtedly distinctive in many other respects. However, like many other countries on the list, Nauru lacks a permanent standing army or other form of armed force.

The nation doesn't even have a capital, probably because of its size. The nation does have a Nauru Police Force, despite its little size, which is used to make sure that the nation can maintain order. The nation, which is situated in the Micronesian archipelago of hundreds of tiny islands, is primarily dependent on its easily available phosphate. Today, the nation maintains strong ties with neighboring Micronesia islands as well as adjacent Australia. According to a rumored unofficial agreement between Nauru and Australia, Australia would provide for the country's basic military requirements. In fact, when Germany attacked Nauru in December 1940, the Australian Navy was requested to provide the necessary defense.