On July 6, the impish economic historian Niall Ferguson took the podium at the Aspen Ideas Festival, an annual seminar series for the rich and powerful on how to remain rich and powerful. Ferguson, as is his wont, began by tweaking the perpetual American reluctance to admit that the United States is an empire. “You’re the redcoats now,” the Oxford-trained Scot said in a stage whisper.

Ferguson meant no offense. To the contrary, he is well known for wishing that the US -- which he calls a “colossus with an attention-deficit disorder” -- would embrace its imperial charge with the sober, resigned enthusiasm once displayed in London. Like many on the American right, he worries that major social investments like Social Security and Medicare will sap the Treasury to the point that massive expenditures on the Pentagon will become fiscally or politically untenable. Back in needling mode, he notes that republics become empires when they begin to delegate diplomatic functions to the military. The US passed this milestone long ago and, Ferguson continues seriously, it should not look back. It is natural that, being better-heeled and having more boots on the ground than the civilian diplomats, military emissaries should become the executors of the imperial capital’s foreign policy.

The latest development in the devolution of US foreign policy tasks to the military is the creation of the US Africa Command, or AFRICOM, in 2007. Despite the murmurs from Defense Secretary Robert Gates about “excessive militarization” of US overseas activity, the Obama administration has kept AFRICOM’s deployment right on schedule. AFRICOM has an area of operations stretching from Casablanca to Capetown, excluding Egypt, but including the North African nations previously watched over by the European Command and the Horn of Africa hot spots formerly policed by Central Command. Among the active missions now run by AFRICOM are the Pan-Sahel Initiative, a collaborative effort with North African countries to flush radical Islamists from desert hideouts, and the participation of the US Navy in patrols for pirates in the Red Sea and Indian Ocean. Sudan, Somalia, Ethiopia, Eritrea -- there is a long list of potential sites for intervention in the eastern half of the continent alone.

Vice Adm. Robert Moeller, the retired deputy head of AFRICOM, insisted in the July 21 edition of Foreign Policy that the structure’s purpose is benign. “US security interests in Africa,” he wrote, “are best served by building long-term partnerships with African nations, regional organizations and the African Union.” Such bland phrases have the dual virtue of lulling most readers to sleep even as they thrill the likes of Ferguson with their offhand acceptance of the notion that the US has “security interests” in Africa. Officials are rarely challenged in public forums to elucidate what these “interests” might be, but as shown by Resist AFRICOM, a coalition of left-leaning American NGOs, the new command has done so in several briefings. The first two strategic objectives of AFRICOM are to prevent African locales from becoming “safe havens” for al-Qaeda and other radical Islamist groups and to safeguard oil deposits. As George Trumbull observes in this issue, these goals are familiar from preceding decades of US Africa policy, if one substitutes communism for Islamism. The US has long recognized that shipping lanes off African shores are conduits for the flow of the world’s oil supply, and in the twenty-first century one can add that the US buys about one quarter of its own oil from African suppliers. The third core aim of AFRICOM, however, is new: to check the growing interest of China in African oil and other natural resources.

China, by the best accounts, is nowhere near a decision to attempt a challenge to the global military supremacy of the United States. Beijing is content, like Europe and Japan, to reap the benefits of US force projection capability -- chiefly, the Fifth Fleet’s protective hug of the petroleum jackpot in the Persian Gulf. The rapid growth of the Chinese economy, moreover. depends in large part on consumption of Chinese manufactures in the world’s largest market, meaning that Beijing has a strong interest in US financial health as well. Still, the bipartisan post-Cold War project of extending Washington’s sole superpower status indefinitely requires that US strategists peer far into the future to identify contenders for the throne. The anti-Chinese aspect of AFRICOM is of a piece with the “area access denial” maneuvers of the Cold War era. Even if Washington cannot establish a foothold in Africa, it should endeavor to deny one to Beijng. Such aspirations give new meaning to Moeller’s quip that the command is working on “African time.”

Moeller was also at pains to counter the criticism, advanced by Resist AFRICOM and others, that AFRICOM will impinge upon the domain of the State Department. He assured critics, for instance, that officers visiting African countries from the command’s headquarters in Stuttgart, Germany will report to the ambassadors. Most important, he said, AFRICOM does not make policy. This statement, again, has the double value of being banal and deeply misleading. US foreign policy is not made in any single government office, certainly not in the State Department, but through a constant push and pull of lobbying of the White House (which has its own predilections) by actors inside and outside government, and inside and outside the United States. Not only is the military one of these actors, it is an extremely powerful one, providing hundreds of thousands of jobs and marshaling loyal support in Congress, among other advantages. The reason to fear “excessive militarization” of US policy in Africa is not that AFRICOM personnel will call the shots, but that the orders coming from Washington will already have been shaped by the Pentagon’s prerogatives and promises to deliver results where diplomats can only talk.

To Ferguson and his ilk, the US empire is necessary as the praetorian guard of the liberal capitalist order and the only power that can bring stability to, or at least contain instability in, unruly places like AFRICOM’s area of operations. Past empires built railways and schools; today’s nab pirates and transfer technocratic know-how. Empires, Ferguson believes, should invest what it takes to do the job, even if it means cutting domestic spending. The costs of imperial intervention to places like Africa do not figure.

For most of the American elite, the relentless expansion of the national security state is simply business as usual. In Aspen, Niall Ferguson was asked why it matters if the country he chides for being an “empire in denial” loses some of its clout. “Having grown up in a declining empire,” he replied with characteristic dry wit, “I do not recommend it.” He instructed his audience that the US is approaching another dangerous moment of truth: In five years, the cost of servicing the national debt will be larger than the defense budget. When that happens, he warned, empires fall.