An empire is defined as "an aggregate of nations or people ruled over by an emperor or other powerful sovereign or government...

The term "empire" is associated with other words such as imperialism, colonialism, and globalization. 

An imperial political structure can be established and maintained in two ways: (i) as a territorial empire of direct conquest and control with force or (ii) as a coercive, hegemonic empire of indirect conquest and control with power. The former method provides greater tribute and direct political control, yet limits further expansion because it absorbs military forces to fixed garrisons.

in American society throughout its entire history. As David Ludden explains, “journalists, scholars, teachers, students, analysts, and politicians prefer to depict the U.S. as a nation pursuing its own interests and ideals.”  This often results in imperialist endeavors being presented as measures taken to enhance national security. Ludden explains this phenomenon with the concept of “ideological blinders”, which he says prevent American citizens from realizing the true nature of America’s current systems and strategies. These “ideological blinders” that people wear have resulted in an “invisible” American empire of which most American citizens are unaware.