Peter Carthage is an employee of, and chief troubleshooter for, WAR.
With a company name of Weapons Analysis and Research, Incorporated, abbreviated WAR, it would be easy to expect a mercenary outfit but that is not the case with this organization whose lead agent, or representative, is Peter Carthage. The purpose of WAR, Inc. is to provide just about everything else: training, equipment, systems, and advice.
The company, based in New Jersey, was founded to fill a vacuum. Many smaller third-world countries were in need of assistance to defend themselves but in the world of two super-powers, getting it without unwanted strings was difficult. Ask the U.S. and the country was suddenly a die-hard anti-communist, possibly even an imperialist. Ask the Soviet and it was a Red-loving, freedom-hating socialist. So War, Inc was there to let the country be itself, for a price. And with the hiring came the services of Carthage, known best as the Expeditor.
Carthage is a man used to wearing suits for meetings with the clients and fatigues for work in the field. Whether it is a briefcase or an automatic in his hand, he is able to handle the job. He doesn't particularly want to fight. He wants to sell the tools for others to fight. He also doesn't want to get killed, though, so fighting becomes necessary and when it does, having an intimate knowledge of the tools of the trade is one very good bonus.
Note: this series had two names to it, which is odd considering there are only 3 books. The first is The Man From WAR and that other is The Mission Series.