In the spring of 2007 a tiny military contractor with a slender track record went shopping for a precious Beltway commodity.

The company, Defense Solutions, sought the services of a retired general with national stature, someone who could open doors at the highest levels of government and help it win a huge prize: the right to supply Iraq with thousands of armored vehicles.

Access like this does not come cheap, but it was an opportunity potentially worth billions in sales, and Defense Solutions soon found its man. The company signed Barry R. McCaffrey, a retired four-star Army general and military analyst for NBC News, to a consulting contract starting June 15, 2007.

Four days later the general swung into action. He sent a personal note and 15-page briefing packet to David H. Petraeus, the commanding general in Iraq, strongly recommending Defense Solutions and its offer to supply Iraq with 5,000 armored vehicles from Eastern Europe. “No other proposal is quicker, less costly, or more certain to succeed,” he said.

Thus, within days of hiring General McCaffrey, the Defense Solutions sales pitch was in the hands of the American commander with the greatest influence over Iraq’s expanding military.

“That’s what I pay him for,” Timothy D. Ringgold, chief executive of Defense Solutions, said in an interview.