1 Vatican City
The State of Vatican City is an enclave country which lies entirely within Rome, the capital of Italy. This city does not have any armed forced till now but informally the Italian Armed Forces protect Vatican City.
Andorra, officially the Principality of Andorra is the sixth-smallest nation in Europe, having an area of 468 km2 (181 sq mi) and a population of approximately 77,281. Andorra has no regular army however signed treaties with European country and France for its protection. Its little volunteer army is solely ceremonial in operate. The paramilitary GIPA (trained in counter-terrorism and prisoner management) is a component of the national police.
The Republic of Palau, located in the North Pacific Ocean, is famous for its snorkeling sites and scuba diving. Despite the lack of a national military force, Palau does have a Palau National Police section that was created to provide the necessary protection for civilians.
The Republic of Nauru is the world's smallest island nation with a population of just under 10000 inhabitants. It has had no standing army since becoming independent from New Zealand in 1962. Australia is responsible for Nauru's defense under an informal agreement between the two countries. However, there is a relatively large armed police force, and an auxiliary police force for internal security.
Grenada is an island country consisting of the island of Grenada and six smaller islands at the southern end of the Grenadines in the southeastern Caribbean Sea. This island nation abolished its army since 1983. The Royal Grenada Police Force maintains a paramilitary special service unit for internal security purposes. Defense is the responsibility of the Regional Security System.