Michael Cantrell, an engineer at the Army Space and Missile Defense Command headquarters in Huntsville, Ala., along with his deputy, Doug Ennis, had lined up millions of dollars from Congress for defense companies. Mr. Cantrell decided it was time to take a cut. Within months, [he] began getting personal checks from contractors and later [picked] up a briefcase stuffed with $75,000. The two men eventually collected more than $1.6 million in kickbacks, through 2007, [causing] them to plead guilty this year to corruption charges. But what has drawn little scrutiny are [Cantrell's] activities leading up to it. Thanks to important allies in Congress, he extracted nearly $350 million for projects the Pentagon did not want, wasting taxpayer money on what would become dead-end ventures. He often bypassed his bosses and broke department rules to make his case on Capitol Hill. He enlisted contractors to pitch projects that would keep the dollars flowing and paid lobbyists to ease them through. He cultivated lawmakers, who were eager to send money back home or to favored contractors and did not ask many questions. And when he ran into trouble, he could count on his powerful friends for protection from Pentagon officials who provided little oversight and were afraid of alienating lawmakers. I could go over to the Hill and put pressure on people above me and get something done," Mr. Cantrell explained. "With the Army, as long as the senator is not calling over and complaining, everything is O.K. And the senator will not call over and complain unless the contractor you're working with does not get his money. So you just have to keep the players happy and it works."