No matter which candidate takes the presidential oath in January, he'll take command of two military forces in Iraq -- one made up of regular GIs, the other consisting of mercenaries. Any idea which one is larger? It's the mercenary force.

That's just one of the findings in two new government studies examining the use of private contractors in Iraq.

Post surge, the U.S. has about 150,000 men and women deployed in the Iraqi theater. The Congressional Budget Office estimates there are another 190,000 contractors drawing a U.S. taxpayer-funded check. The CBO places the public cost of this private army at $100 billion since 2003.

Contracting out parts of a war effort is not revolutionary. It dates, in fact, to the American Revolution. But the level of private contracting in Iraq is notable -- 2.5 times higher than in any other major U.S. conflict, although roughly comparable to the Clinton-era operation in the Balkans.

It's important to note the overwhelming majority of these hired guns don't carry guns at all. Approximately 160,000 of these contractors perform non-combat functions such as administration, construction, maintenance, transportation and housekeeping. Forty percent are Iraqi nationals; only 20 percent are U.S. citizens.

The remaining 30,000 contractors are literally hired guns. In addition to providing protection to coalition and Iraqi officials, private security contractors (PSCs) protect other contractors.

In theory this makes a lot of sense. Instead of using soldiers to chauffeur a diplomat across Baghdad or accompany an electrician outside the Green Zone, PSCs free up military personnel to go after the terrorists who created the need for security in the first place.

But the real world has a propensity to blow up theories, particularly in war zones where explosions aren't theoretical. The most consequential question facing military and civilian authorities once the shooting starts is this: Who has authority over the PSCs?

As the CBO and a similar report issued by the Government Accountability Office point out, it depends on who's asking and who's answering.

A cut-and-dried jurisdictional question in the states becomes an international quandary when it comes to PSCs. Today, a contractor working in Iraq accused of a crime could be brought before an Iraqi or International Criminal Court, unless he or she has been provided immunity by the Coalition Provisional Authority or the United Nations. That immunity runs out in December and has been a major sticking point in a status of forces agreement being negotiated by the U.S and Iraqi governments.

A contractor can also be court-martialed under the Uniform Code of Military Justice (UCMJ). In 2006, Congress extended UCMJ authority to civilians supporting deployed troops. In March the Department of Defense used that authority to convict a private contractor of charges stemming from an assault. He was sentenced to five months in the brig.

A contractor can also be punished under the Military Extraterritorial Jurisdiction Act of 2000, a law that allows a Defense Department civilian accused of committing a felony overseas to be tried under U.S courts.

That ain't all, folks. Other laws pertinent to contractors include maritime provisions, the Patriot Act, the War Crimes Act of 1996, the Military Commissions Act of 2006 and so on. This doesn't include the Laws of Armed Conflict drawn up under the Geneva Conventions.

With so many laws, you might think our military would have plenty of authority over private contractors. It doesn't. In her book "Betraying Our Troops," Dina Rasor documents plenty of instances in which private contractors simply quit and went home once the shooting started. Worse, some contractors supporting combat operations withheld supplies and services until they were paid in full. In other cases, private providers refused to help because the support our military asked for wasn't in the original contract.

President McCain or President Obama, take note: This is no way to run a war.

Thankfully, both have committed to significantly expanding the military. That should lessen or eliminate dependence on armed contractors. When the bullets fly, our troops need to be supported by people motivated by patriotism, not profits.

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