"Corporate Warriors: The Rise of the Privatized Military Industry and Its Ramifications for International Security" by P. W. Singer, in International Security (Winter 2001-02), MIT Press Journals, 5 Cambridge Ctr., 4th fl., Cambridge, Mass. 02142.

Need a commando unit? A fighter wing? A new breed of corporate mercenaries stands ready to provide them. Private military firms (PMFs) are in the business of selling the specialized services needed to fight today´s high-tech wars, from military training and logistical support to combat forces. "The emergence of PMFs," declares Singer, a Brookings Institution researcher, "challenges one of the basic premises of international security: that states possess a monopoly over the use of force."

The mercenary profession is as old as warfare itself--the Thirty Years´ War of 1618-48 was fought largely by hired hands--but with the rise of the modern state in the last century or so, hired guns slipped into the shadows. Now for-profit fighters are back, though better organized and disciplined than they were before. Much of the work is done far from the front lines. Firms such as MPRI, ArmorGroup, and Vinnell are hierarchical, registered businesses that "compete openly on the international market" and even advertise on the World Wide Web. ("The greatest corporate assemblage of military expertise in the world," is how MPRI describes itself.) Other firms, such as DynCorp., are "military oriented."

PMFs do contract work in communications and computers at Cheyenne Mountain, the nerve center of the U.S. nuclear arsenal, and they provide Saudi Arabia with everything from air defense to naval training. Every major U.S. military operation in the post-Cold War era has involved significant PMF support, Singer notes. The firms have been "determinate actors" in conflicts in Angola, Croatia, Eritrea and Ethiopia, and Sierra Leone.

The technology-oriented "revolution in military affairs" and large-scale demilitarization since the end of the Cold War have fed today´s rapid PMF growth. In the 1990s alone the world´s armies shrank by more than six million, creating a large pool of well-trained labor. Some former elite military units, such as the South African 32nd Reconnaissance Battalion, have simply opened up shop as companies. It is estimated that 70 percent of the KGB found work with PMFs once the Soviet spy agency went belly-up. At the same time, technological change in the world´s militaries has created strong demand for highly skilled people, even if they don´t wear uniforms.

The rise of PMFs has tremendous implications for international security, Singer argues. By providing sophisticated off-the-shelf military muscle, PMFs can empower weak states and "non-state actors," such as guerilla and terrorist groups. Employed by civilian regimes in Third World states, they may help stave off military coups. By lowering the cost of obtaining sophisticated military force, they may increase the overall likelihood of war; by enabling weak states to buy a potent defense on the open market, they may diminish it. Ultimately, Singer speculates, we may be on the road back to the environment of old Europe, "where wealth and military capability went hand in hand: Pecunia nervus belli (Money nourishes war)."