The United Nations has issued a new warning over the role of private military firms in Iraq and Afghanistan. In a report set for release today, the U.N. calls the reliance on private companies “new modalities of mercenarism.” The report says private guards are akin to “irregular combatants.” The private military industry has come under unprecedented scrutiny following the September killing of 17 Iraqis by Blackwater guards. The U.N. panel says more countries should sign on to the International Convention Against the Recruitment, Use, Financing and Training of Mercenaries. Only 30 governments have ratified so far.