A coup d'etat is a

forcible overthrow of government.

lessening of government control over the economy.

period of economic decline.

reduction of Cold War tensions.

A coup d'etat, also known as a coup or a putsch, is a forcible (often illegal) overthrow of government.

A lessening of government control over the economy is something we can call Laissez-faire politics.

A period of economic decline is known as a recession.

We use the term Détente (French for 'relaxation') when we talk about reduction in Cold War tensions.