As economies, societies, and cultures have become increasingly interconnected, the traditional conception of threats to security as stemming from identifiable sources in individual countries has become antiquated. Today, many threats are stateless in origin and transnational in scope. Terrorist groups such as Hezbollah and al Qaeda have cells in multiple countries, often operating without the active support of any government but still capable of committing attacks with global impact. Both 9/11 and the unsuccessful plot to blow up airliners over the Atlantic Ocean in 2006 were aimed at disrupting the global air-transportation network. Potentially crippling attacks on the power grid or financial institutions could come from a computer anywhere in the world.
Fighting elusive and transnational enemies that do not respect the traditional conventions of warfare requires international cooperation. Terrorists are unlike the United States' past enemies. Whereas the Soviet Union had a defined territory with infrastructure and resources that could be targeted in retaliation for any aggression committed against the United States, terrorist groups have no established boundaries. A strategy of deterrence through threats of retaliation would prove ineffective against terrorists, since so many are willing to die for their cause. Moreover, they often strike at global or transnational targets, seeking to exploit the seams between national jurisdictions, where enforcement may be shared, ambiguous, or inconsistent.
In light of these developments, the field of international law is taking on greater relevance. Since 9/11, it has been central to discussions about the "war on terror," on issues ranging from the treatment of enemy combatants to the standards of security that should apply to global trade and travel. Unfortunately, just as international law is becoming more relevant, its objectivity is becoming more questionable. Some in the international legal community see international law as a means for advancing political agendas against the United States rather than as a valuable tool for addressing increasingly global concerns. Employing the rhetoric of international law, critics of the United States have challenged everything from its foreign and homeland security policies