Final answer:
Estonia gained its independence from the Soviet Union in 1991, transitioning to a market economy and democratic government, and later joining the EU and NATO.
Step-by-step explanation:
Estonia gained its independence from the Soviet Union in 1991. This event was part of a larger movement in the late 1980s and early 1990s when many republics sought independence following political reforms and the decline of centralized Communist power in Moscow. Unlike Belarus, which maintained a close relationship with Russia, Estonia, along with Latvia and Lithuania, sought to integrate with Western Europe and its economic systems. The transition for these Baltic Republics was marked by a rapid shift to market economies, democratic governance, and later, membership in both the European Union (EU) and North Atlantic Treaty Organization (NATO) in 2004. The dissolution of the Soviet Union culminated in the establishment of the Commonwealth of Independent States in December 1991, which saw eleven of the former Soviet republics reorganize into a looser confederation as independent nations.