“The problem with Rumsfeld’s blunt statement [that the American goal was to kill as many Taliban soldiers and al-Qaeda members as possible], as with other similar phenomena like the uncertain status of the Afghan prisoners at Guantanamo Bay, is that they seem to point directly to Agamben’s distinction between the full citizen and Homo sacer who, although he or she is alive as a human being, is not part of the political community.”
—Slavoj Žižek, Welcome to the Desert of the Real
Whatever else it is, Giorgio Agamben’s philosophy is anti-authoritarian and anti-totalitarianism. Slavoj Žižek draws from Agamben to round out Welcome to the Desert of the Real. Specifically, Žižek draws from Agamben’s theories about homo sacer and “the state of exception,” the latter of which Agamben borrows from the German jurisprudent Carl Schmitt. In his book Homo Sacer, Agamben adopts Pompeius Festus’ definition of homo sacer as “the one whom the people have judged on account of a crime,” and the one who cannot be sacrificed, but can be killed without legal consequence.
Agamben suggests that homo sacer is bound up with notions of sovereignty. Sovereignty is determined by what is included and what is excluded from the jurisdiction of a sovereign. Although a sovereign has the power to suspend the validity of law and, therefore, to stand outside the law, the sovereign may lose that privilege and become the sacred man who no longer has rights granted and secured by the polis, and who may be killed, but not sacrificed. According to this paradigm, the sovereign is a man—a king or a monarch—who embodies statehood and sovereignty. The body of this man is itself the site of law so long as the man remains the sovereign; as soon as the man is no longer sovereign, his body ceases to be the site of the law.
Žižek seems less concerned with the idea of sovereignty implicated by the term homo sacer. He focuses, instead, on the “outsider,” “fugitive,” or “noncitizen” aspect of homo sacer. He defines today’s homo sacer as “the privileged object of humanitarian biopolitics: the one who is deprived of his or her full humanity being taken care of in a very patronizing way.” Žižek’s examples of today’s homo sacer include John Walker, the American who fought with the Taliban; the sans papers in France; the inhabitants of the favelas in Brazil; people in the African-American ghettos in the United States; an American war plane flying above Afghanistan; and others. None of these examples describes groups or persons who once enjoyed the power of a sovereign. All of these groups or persons have in common an ambiguous status in relation to the law of the polis.
Žižek shares with Agamben the notion that homo sacer is, or can be, the embodiment of the state of exception: the one who is excluded from the polis, who neither makes laws nor enjoys the protection of laws. By sidestepping Agamben’s proposition that the sovereign body is the constitution of sovereignty—a move that might have to do with Žižek’s criticism of Agamben as wedded to the dialectics of the Enlightenment and to Foucault’s disciplinary power or biopower—Žižek is able to raise profound and troubling questions about the status of every one of us regarding homo sacer. He asks, for instance, “What if the true problem is not the fragile status of the excluded but, rather, the fact that, on the most elementary level, we are all ‘excluded’ in the sense that our most elementary, ‘zero’ position is that of an object of biopolitics, and that possible political and citizenship rights are given to us as a secondary gesture, in accordance with biopolitical strategic considerations?” Žižek does not answer this question, but the answer, disturbing as it is, seems implied in the question.
 Giorgio Agamben. Homo Sacer: Sovereign Power and Bare Life. Stanford University Press, 1995. Pg. 71.