Colonel Thomas X. Hammes is a retired U.S. Marine officer and counter-insurgency warfare specialist.
In this work, Sword Out Of The Stone: On War in the 21st Century, he openly criticized The Pentagon and the Joint Chiefs of Staff.
[6] In September 2006, Hammes was one of the retired U.S. military officers who, along with Generals John Batiste and Paul Eaton, called for Secretary of Defense Donald Rumsfeld to resign.
They appeared in front of the Senate Democratic Policy Committee to testify, the first prominent U.S. military officials to publicly criticize Rumsfeld.
[9] Hammes also appeared on the PBS documentary series Frontline where he criticized the use of private contractors in Iraq.