Original sentence: The annexation of Crimea by the Russian Federation is a disputed annexation process that began following Russian intervened the Autonomous Republic of Crimea and the city of Sevastopol, provinces of Ukraine, and after unrecognized local authorities declared their independence from Ukraine
Edited sentence: The annexation of Crimea by the Russian Federation is a disputed annexation process that began after Russia invaded the Autonomous Republic of Crimea and the city of Sevastopol, provinces of Ukraine, and after unrecognized local authorities appointed by Russia declared their independence from Ukraine