In his new book, The Case for Goliath: How America Acts As the World's Government in the 21st Century, author Michael Mandelbaum argues that, contrary to the perception held by some that America is a threatening, heavily-armed giant, "American power helps to make other countries more secure and, by keeping the international economy working smoothly, also makes others more prosperous than they otherwise would be."

Mandelbaum stated that his controversial thesis is encapsulated in the subtitle of the book. The use of the word "government" is useful for four reasons. First, it tells us something about the world, which is increasingly connected through transportation, information flows, and global commerce. Second, it tells us something about the United States, which plays an unprecedented role in the international system: "superpower" does not capture it, nor does "empire" (since the United States does not exert direct control over other states). Third, the term tells us something about other countries – that despite criticism of the United States, no concerted opposition has emerged (as realist balance-of-power theory would have predicted) to challenge U.S. primacy. The absence of overt balancing, Mandelbaum argued, is indicative of the extent to which other countries do not feel threatened by the U.S. global role, and indeed benefit enormously by it. Fourth, and finally, the use of the term "government" is accurate because of the indispensable role that the United States plays in preserving international order. In East Asia and Western Europe, the U.S. military presence provides reassurance and serves as a pacifier preventing the resurgence of regional military rivalries. The United States also takes the lead in forestalling the proliferation of nuclear and unconventional weapons. U.S. policies toward Iraq, North Korea, and Iran are controversial, but the expectation among other countries is that the United States will take the lead.

Mandelbaum argued that the real reason for the war in Iraq was not the one publicized. The defensible reason for a preventive war was to prevent Saddam Hussein from eventually acting upon his intention to reconstitute his nuclear weapons program. In initiating a preventive war, the Bush administration was acting upon the post-9/11 doctrine enunciated in its September 2002 National Security Strategy report, which stated that the United States would act against emerging threats. But Mandelbaum argued that the Iraq war would not set a precedent for three reasons: the aftermath in Iraq has turned out badly; other potential targets (Iran and North Korea) do no not lend themselves to the Iraq model; and the U.S.-led invasion, without the legitimizing imprimatur of the UN Security Council, was contrary to the principle of international sovereignty. While President Bush's attitude toward the use of force is often contrasted with that of President Clinton, Mandelbaum argued that the Bush administration's preventive wars in Iraq and Afghanistan is a "fraternal twin" of the Clinton administration's humanitarian interventions in the 1990s. Both have led to state-building missions, which the United States does not like to do, and, moreover, does not do well.

The U.S. global economic role complements that in the security area: U.S. fleets maintain the international sea lanes, the dollar remains the world's reserve currency, the United States (through the IMF) is the lender of last resort, as well as the consumer of last resort (though that has produced a massive trade deficit).

Mandelbaum stated that his chief focus of U.S. policy is in the energy area, where U.S. consumption puts the country at the mercy of antidemocratic governments that are funding international terrorism. He concluded by observing that U.S. primacy is likely to continue because no other power will be able to play the role that United States currently does, preferring instead to remain "free riders" on the U.S.-maintained security system. The major challenge that Mandelbaum sees on the horizon is internal rather than external: the concern that entitlement spending in the U.S. federal budget will crowd out funding for a continued activist U.S. global role. As Mandelbaum put it, "the greatest threat to the U.S. global role is not China, but Medicare."