Which term refers to a government run by a small group of military officers?

The term that refers to a government run by a small group of military officers is "junta." A junta is typically formed following a coup d'état, which is when a group, often including military leaders, takes control of the government by force. This form of governance usually involves the suspension of constitutional rights and can lead to the centralization of power in the hands of a few individuals or a small group, undermining democratic processes.

The other terms relate to different governmental structures. A dictatorship is ruled by a single individual with absolute power, while an oligarchy refers to a system where a small group of elites hold power, but not necessarily military in nature. Totalitarianism describes a political system where the state seeks to control every aspect of public and private life, which can include military influences but is broader in scope than just a military-led government. Thus, "junta" specifically captures the essence of a military-led governance structure, making it the correct answer.