When something is dissolved, it means that it has come to an end or been terminated. In the context of the Soviet Union, it refers to the official disbanding of the USSR as a political entity in 1991.
Related terms
Collapse: The sudden failure or breakdown of a system or organization.
Independence: The state of being self-governing and free from outside control.
Post-Soviet States: Refers to the countries that emerged after the dissolution of the Soviet Union, such as Russia, Ukraine, Belarus, and others.