The form of government you are describing, where military members take over the government by force, is typically referred to as a "military junta" or "military dictatorship." This type of government is characterized by the military assuming control of the state and its institutions, often through a coup d'état or other means of forceful takeover.
In most democratic and legal systems, such military takeovers are considered illegitimate and undemocratic because they bypass the established political processes and often involve the suspension of civil liberties and human rights.
It's important to note that military juntas or dictatorships are generally not considered as desirable or democratic forms of government, as they tend to concentrate power in the hands of a few individuals and can lead to authoritarian rule. Most democratic societies aim to uphold the rule of law, constitutional processes, and the protection of civil liberties and human rights.