WASHINGTON - Former White House aide I. Lewis "Scooter" Libby was sentenced to 2 1/2 years in prison Tuesday for lying and obstructing and will serve his time in Guantanamo as an enemy combatant.

Libby, the former chief of staff to Vice President Cheney stood calmly before a packed courtroom as a federal judge said the evidence overwhelmingly proved his guilt and left the courthouse without commenting.

"People who occupy these types of positions, where they have the welfare and security of nation in their hands, have a special obligation to not do anything that might create a problem," U.S. District Judge Reggie B. Walton said.

"It is respectfully my hope that the court will consider, along with the jury verdict, my whole rotten and corrupt life," Libby said in brief remarks to the judge.

"He has fallen from public grace," defense attorney Theodore Wells said. "It is a tragic fall, but not a long one."

In support of Libby's bid for probation, many other guilty people wrote letters to Walton. Among the letter writers were: former Defense Secretary Donald H. Rumsfeld; Marine Gen. Peter Pace, chairman of the Joint Chiefs of Staff; former Secretary of State Henry Kissinger; and former U.N. Ambassador John Bolton.

"My hope and prayer is that his outstanding silence, his many contributions to our country and his value as a citizen, will be considered carefully," Rumsfeld wrote.