Killing one's fellow species for no reason other than psychopathic fun and profit seems repulsive. But in today's New World Order, the enlistment of mercenaries to massacre one's enemies is getting a big thumbs-up. "Soldiers of fortune" are now, bizarrely enough, regarded by many political observers as a financially and morally superior replacement to the clumsy draft-the-citizenry-and-train-them-to-destroy method that governments have long maintained.

Mercenaries have a long, bloody history of annihilating humans for cold hard cash. Huge, hairy Gauls stocked the Roman phalanxes; Hessians were hired by the British to perform their filthy colonial chores; 1960s vipers like "Mad" Mike Hoare and Bob Denard pillaged the Congo and Indian Ocean archipelagos. Mercs' well-earned reputation as sadistic slaughterers-for-hire has been shattered in the last eight years, though, by three organizations that coolly operate with impeccable behavior.

Executive Outcomes (EO) of South Africa, though it has now closed shop, serves as today's prototype for civilized mercenary activity. This Pretoria-based outfit boasted a multiracial force (70 percent black) of between 500 and 2,000 soldiers, primarily battle-toughened veterans from apartheid-era special forces. The commando-killers were paid the equivalent of between U.S. $2,700 per month for basic infantry mayhem and $13,000 per month for bomber pilots. Life insurance was duly included.

EO's first spectacular assignment arrived in March 1993, when it was commissioned by the government of Angola to recapture a oil refinery that UNITA guerrillas had seized. With Ramboesque efficiency, 50 EO officers trained and led 600 Angolan troops in a victorious assault in which only three soldiers were wounded. The impressed Angolans next hired EO to protect its diamond mines: Continued success eventually earned the mercs more than $100 million.

Sierra Leone was EO's next destination -- in 1995. With only 170 men and six aircraft, the foreign pros managed to miraculously quell a civil war. The subsequent calm enabled the population to hold the first democratic elections in 28 years. Only two mercs were killed, and EO picked up another check for $35 million -- a small bill for national peace.

Executive Outcomes also supplied soldiers to Uganda, Mozambique, and Kenya, to aid regimes that were struggling against internal chaos. International admiration for its battle prowess ensued, with a grudging reappraisal of mercenary potential. "I think there's a place for these companies," suggested Canadian Brigadier General Ian Douglas to United Nations officials. "You have to stop violence before you can start negotiations. Executive Outcomes did that in nine days (in Sierra Leone). They literally stopped the war."

On January 1, 1999, EO abruptly closed its Pretoria business, prompted perhaps by recent South African "no-merc" legislation that prohibits the bartering of armed conflict for personal profit. Today, EO's staff and expertise has been transferred to its once-subsidiary operations: LifeGuard in Sierra Leone and Saracen in Angola.

Sandline International (SI) is now the world's highest-profile private army. Its leader, rugged ex-British colonel Tim Spicer, has a killer resume after serving in the Falklands and as an advisor to top commanders in the Gulf War and Bosnia.

Spicer's first deep-pocket client was President Sir Julius Chan of Papua New Guinea (PNG). In secret deals, Chan promised to pay the merc $36 million if he could recapture copper mines that were occupied by the separatists of Bougainville Island. In 1997, Colonel Tim flew in 70 commandos and planned helicopter attacks on rebel villages, but his plans were aborted when envious PNG generals discovered the heft of his salary and capriciously jailed him for three weeks. Upon release, Tim badgered an international tribunal that finally forced PNG to fork over the money.

Sandline's next operation was in 1998 in Sierra Leone, that hellhole of amputation-by-machete violence. Ignoring an impotent United Nations resolution that outlawed weapons delivery, Spicer shuttled in 35 tons of Bulgarian guns and ammo and trained 40,000 local fighters who successfully reinstalled the ousted President, Ahmed Tejan Kabbah. Spicer's tab for this two-month chore was $10 million.

The mightiest American merc corporation is Military Professional Resources Inc., (MPRI) headquartered in Virginia. Composed of 350 staff and 2,000 ex-officers on retainer, its extensive international sector is run by General Carl Vuono, the Desert Storm Army commander. MPRI's predominant achievement was training the Croatian army that invaded and quickly captured Serb-held Krajina in 1995. Later it trained the Bosnians for "tens of millions of dollars," admitted Bosnia's UN ambassador. Obviously, MPRI's activities were condoned by Washington, which was ecstatic to have someone doing this war work.

Dozens of other mercenary brigades, often euphemistically titled "security forces," are presently in existence worldwide. AirScan of Florida operates an air force that protects African oil fields. Gurkha Security Guards dispatches Nepalese soldiers to watchdog international mining operations. Defense Services Ltd. (DSL) earns over $100 million annually in a host of functions, including support for the hapless United Nations military. Vinnell Corporation operated covertly in Vietnam and has been employed by Saudi Arabia since 1995.

Beneath this upper echelon of First World assassins there exist myriad mercs operating in (at least) Tajikistan, Armenia, Azerbaijan, Afghanistan, Kashmir, Angola, Congo, Rwanda, Iraq, Colombia and probably every province of the former Yugoslavia.

Amnesty International and other peace-rabid organizations deplore private armies, but neither AI nor Human Rights Watch have been successful at blaming atrocities on EO, SI, or MPRI. The truth is, modern mercs with their expertise and swift deployment have tremendous potential to halt violence. UN Secretary General Kofi Annan lamented after the Rwandan genocide of 1993-'94 that "If I had one reinforced brigade -- well-trained and well-equipped -- I could have saved hundreds of thousands of lives." He should have telephoned Tim Spicer or Carl Vuono.

But to depict mercenaries solely as brave agents of future peace is naive and obtuse. Obviously, a dark potential exists: If private armies grow grossly powerful, what will prevent them from toppling all governments? Could a union of private armies conquer the earth, like rogue Caesars? Would victorious war-chiefs rule over the idiots that trusted them?

Mercenaries are sturdy problem-solvers in certain global emergencies, but if we don't keep a tight leash on them, these "dogs of war" might devour us.

Hank Hyena is a columnist for SFGate.com and SF Metropolitan, and a frequent contributor to Salon.