Malaysia–Singapore border territories when Johor became a British protectorate while Singapore remained a British crown colony. On 31 August 1957, the Federation of Malaya (which consisted of only Peninsular Malaysia), which included Johor as a component state, became independent and the Johor–Singapore border again became an international boundary between the sovereign state of Malaya and the self-governing British territory of Singapore. On 16 September 1963, Singapore merged with and become a component state of the Federation of Malaysia, rendering the border between two component states of Malaysia. The border again became an international border when Singapore chose to be separated from Malaysia
Federation in practice highly centralized under the government of the Soviet Union. The Russian Federation has inherited a similar system. Nigeria, Pakistan, India and Malaysia became federations on or shortly before becoming independent from the British Empire. In some recent cases, federations have been instituted as a measure to handle ethnic conflict within a state, such as Bosnia and Herzegovina, and Iraq since 2005. With the United States Constitution having become effective on 4 March 1789, the United States is the oldest surviving federation. On the other end of the timeline is Nepal, which became the newest federation after its constitution