In general, Hardt and Negri theorize an ongoing transition from a "modern" phenomenon of imperialism, centered on individual nation-states, to an emergent postmodern construct created among ruling powers which the authors call "Empire", with different forms of warfare:
...according to Hardt and Negri's Empire, the rise of Empire is the end of nationalconflict, the "enemy" now, whoever he is, can no longer be ideological or national. The enemy now must be understood as a kind of criminal, as someone who represents a threat not to a political system or a nation but to the law. This is the enemy as a terrorist....In the "new order that envelops the entire space of... civilization", where conflict between nations has been made irrelevant, the "enemy" is simultaneously "banalized" and absolutized.
Hardt and Negri elaborate a variety of ideas surrounding constitutions, global war, and class. Hence, the Empire is constituted by a monarchy, an oligarchy and a democracy. Part of the book's analysis deals with "imagin resistance", but "the point of Empire is that it, too, is "total" and that resistance to it can only take the form of negation - "the will to be against". The Empire is total, but economic inequality persists, and as all identities are wiped out and replaced with a universal one, the identity of the poor persists.
This description of pyramidal levels is a replica of Polybius' description of Roman government, hence the denomination "Empire". Furthermore, the crisis is conceived as inherent to the Empire. Hardt and Negri are also heavily indebted to Michel Foucault's analysis of biopolitics and Gilles Deleuze's philosophy. Before Empire, Negri was best known for having written The SavageAnomaly, a milestone book in Spinozism studies which he wrote in prison. Empire is thus, unsurprisingly, also influenced by Spinoza. The ideas first introduced in Empire were further developed in the 2004 books and the 2009 book Commonwealth, which were also written by Hardt and Negri.
Reception
Empire has created important intellectual debates around its arguments. Certain scholars have compared the evolution of the world order with Hardt and Negri's world image in Empire. A number of publications and debates centered on the book. Hardt and Negri's theoretical approach has also been compared and contrasted with works of 'the global capitalism school' whose authors have analyzed transnational capitalism and class relations in the global epoch.