According to nationalists, a nation-state’s government should be

chosen by that nation-state.

Explanation:

A nation state is a state in which most people deliberately share the same cultural values. Actually, nationalism encouraged people with a shared identity to  separate themselves from those who were not like them. As a result, in a nation-state, most people share the same religion.

chosen by the nation state

Explanation:

Nationalism is the ideology that a nation is ideal for polity and each should govern itself. The nationalists believe that a nation should be free from outside control. A nation has a national identity that takes the legitimacy of from the common language, culture or ethnicity. They favor a particular group of people who finds have a common national identity.

to reform the distraught soviet union, the democratization of the communist party was promoted through party secretary mikhail gorbachev's policies of “perestroika” and “glasnost.” perestroika refers to the reconstruction of the political and economic system established by the communist party.