As cheerleaders and detractors now agree, the United States has adopted this global role, and has become an empire, the greatest since Rome. Like all empires, it is compelled to act when threatened, its work is never complete, and it has fostered enemies and challengers. But as debate swirls about whether the American empire serves the broad interests of humanity, many in the United States are wondering if it is even sustainable. The two debates are intertwined, and all are watching, including Osama bin Laden, who is surely enjoying the cost in American lives and the cost to the US Treasury caused by the relentless insurgency in Iraq. He is no doubt also enjoying the disquiet in the heart of the republic. America’s new civil war is a battle not over the notion that freedom is a natural birthright desired by all, but over whether the United States should shoulder the costs of exporting this birthright.

At the height of the Cold War, when there was a visible enemy just as determined as the United States to export its own version of truth, US federal tax revenue fluctuated between 17 and 20 percent of the country’s gdp, and few Americans disputed the need to vanquish the Soviet Union by outspending it on military initiatives. But with the collapse of the Berlin Wall and the so-called “end of history,” a sense of peace and security settled over the United States, leaving it with the relatively inexpensive job of selling democracy to the world’s “failed states.” Americans might have expected lower taxes, but it didn’t work out that way. During the Clinton presidency and the much-vaunted age of globalization, US taxes increased, reaching a high of 21 percent of gdp by the time George W. Bush took office.

When Bush entered the White House he took aim at profligate spending and overseas gambling. Having already indicated that he would be a stay-at-home president, Bush proposed a tax cut of $1.6 trillion (US) over the coming decade, which Congress approved, trimming it to $1.35 trillion, in May 2001. That tax cut has led to a sharp drop in federal tax revenue, from 21 percent to 16 percent of gdp. This might be considered the good-news side of the story. However, in 2000, there was a budget surplus of $236 billion, and the total debt stood at $5.6 trillion; by 2004 the surplus had morphed into a $333-billion deficit, and the debt had grown to an unmanageable $7.8 trillion. What happened?

The answer, according to an increasing number of Americans—60 percent now believe the Iraq war is an unwinnable misadventure—lies in defence spending and homeland security costs. Since the end of the Cold War, US defence spending has followed two distinct trends. Between 1991 and 2001, it remained relatively constant, fluctuating between $266 billion and $305 billion, and representing roughly 16 percent of overall federal spending by the end of the Clinton administration. Since 2001, spending on defence has risen by approximately $50 billion a year, and the total defence expenditures for 2005 might top $500 billion, or over 20 percent of overall federal spending.

The spreading of Jeffersonian ideals and values and the notion that the Constitution has universal applications have always been more liberal than conservative boasts. Lately, they have flipped over to the Republican side, but, as a consequence of overseas extravagance Bush’s empire is in serious disrepair at its very centre. In his travels, Bush is just as likely to meet foreign central bankers who have their grip on America’s fiscal lifeline as he is to meet celebrants of the cause of liberty. Japan and China own nearly $1 trillion in US government securities, and foreigners in general hold over $8 trillion in US financial assets. At the same time, having lost more than a third of its value against the euro since 2001, and with the Chinese yuan attracting new buyers, the US dollar is faltering, putting its position as the world’s reserve currency in peril.

Serious observers recognize that American current accounts and government deficits are not sustainable. And new clouds are forming on the horizon. The United States gained a reprieve of sorts with the failure of the European Union to consolidate around core principles, but if China and India’s growth continues to outpace all others, the time will come when their internal markets are robust enough to no longer be beholden to overseas buyers. At that point, if either of these two nations has imperial aspirations, the shrewdest step would be to foreclose on US debts and bankrupt their competitor.

The cracks in America’s imperial armour, however, are more of the moment. Despite Bush’s late-June address to the nation (from Fort Bragg, North Carolina), in which, vis-à-vis Iraq, he pledged to “stay in the fight until the fight is won,” the US Army was consistently missing its recruitment quotas. With nearly 1,800 American soldiers having come home in body bags, and Iraqi replacements unready in numbers, not even lucrative sign-up inducements seem to be helping America’s volunteer army. New millions have been spent on recruitment drives, but in heartland communities the idea of sacrificing your body for the slippery notion of selling democracy in the streets of Mosul and the deserts of the Middle East is simply not compelling enough. Increasingly at odds with itself and its core values, a distrustful America is now asking if the war on terrorism is responsible for everything from the drive to privatize social security to Bush’s questionable nomination of a unilateralist, John Bolton, as the US ambassador to the UN.

As is the case with all empires, those at the helm of the American empire must ask the crucial question: what imperial frontiers can be sustained at a cost that is not prohibitive? The Romans decided that most Scots and Germans were not worth the outlay in blood and treasure needed to control them. In the United States, mainstream political opinion remains committed to the continuance of the American empire, but the debate over strategy and tactics persists. Multilateralists are prepared to limit the extent of the empire, and understand the need to use soft as well as hard power to achieve their goals, to cajole as well as to conquer. Though under close scrutiny at the moment, the unilateralists now in power believe the stick is mightier than the carrot, and might dare again to thrust the empire into exorbitantly costly conflicts on the frontiers.

No empire can be sustained for long without a ruling class that is prepared to bear its burden. The Roman Empire ultimately collapsed because of an upperclass tax revolt. Similarly, when the French aristocrats refused to pay, their state faltered, and they went to the guillotine during the French Revolution. The British upper classes, on the other hand, were willing to pay the price and, after the happy ending at Waterloo in 1815, they enjoyed a century of low taxation and cheap empire. Do the American upper classes, with their pronounced taste for immediate gratification, have the stomach for a protracted struggle in the Middle East, to say nothing of a possible confrontation with China?

If the first great question concerns the durability of the American empire, the second concerns its utility. A great boast of the English and the Americans at the end of the twentieth century was that their victories over fascism and communism had rid the world of the vicious utopianisms that had been the most dangerous feature of the century. But the collapse of the Soviet Union and its eastern European empire left the United States in a quandary: what to do with its own global military footprint, justified for four decades as containing communism and protecting the free world? Frenzied investment followed the apparent triumph of liberal democracy—to some, the capitalist equivalent of the Marxist notion that under communism the state would eventually wither away—and the playing field became global in scope. But while US reformers looked forward to scaling down costly military installations, for others the victory over communism confirmed that “might is right” and that preparations had to be made for a “new American century.” Keeping military bases intact served the interests of multinational corporations (and kept their confidence up), but US imperial dominion still required an overarching concept. It came in the form of the indispensable-nation theory.