Cowan graduated from the U.S. Naval Academy in 1966 and joined the Marines during the Vietnam War conflict. He subsequently spent three and a half years in Vietnam.
He would later join the elite Delta Force and assist in the rescue of some American citizens who were taken as hostages by Iran in 1979.
Under Ronald Reagan's presidency, he became the only member of the Marines in The Pentagon's special Intelligence Support Activity. Cowan was seriously affected by the bombing of a Marines unit that killed 261 people in Beirut, Lebanon in 1983. He retired from the ISA after what he perceived as an inaction by president Reagan towards dealing with this incident. This inspired him to secretly organize a group that would work outside the government, to help fight terrorism and other social problems worldwide.
After he retired from the ISA, he did work as legistative assistant of senator Warren B. Rudman during the hearings of the Iran Contra scandal.
Cowan was involved in some of the most famous hostage rescues of the Middle East. One of his rescues, the 1990 rescue of American businessmen in Kuwait after Saddam Hussein had invaded that country, was the object of a documentary where some secrets about his organization were revealed, such as the fact that organization operatives used to obtain fake passports issued by a man in Paris to enter countries where people were being held. This operation was conducted in combination with former CIA director Bill Colby.
In addition to his participation as a contributor for Fox, he has also written articles for The Washington Post and been featured in several television shows, (apart from the documentary), such as Larry King Live, Crossfire and others.