General James Clapper, President Barack Obama's nominee for the role of US intelligence chief, is a retired three-star Air Force general and intelligence community veteran.
Most recently he has been serving as undersecretary for intelligence in the Department of Defense, a post that he was appointed to by former President George W Bush in 2007.
President Obama kept him on in the job in 2009.
From 2001-2006 Gen Clapper was director of the National Geospatial-Intelligence Agency, which analyses maps and satellite images.
However, he is said to be a supporter of using more human intelligence alongside technological methods.
Gen Clapper was pushed out from his job at the Geospatial-Intelligence Agency in 2006 by then Defense Secretary Donald Rumsfeld, after telling Congress that he favoured transferring control of his agency away from the Pentagon.
But Robert Gates brought him back to the Department of Defense the following year when he took over from Mr Rumsfeld.
In his most recent role he has overseen the dismantling of the Counterintelligence Field Activity Office, which ran a controversial database holding information on anti-war protests in places such as churches and schools.
He has also called for more transparency and stricter oversight of the treatment of terrorist detainees, according to the Washington Post's WhoRunsGov.com site.
But despite attempting to soften the Pentagon's image, he has been a strong supporter of the wars in Iraq and Afghanistan, the site said.
Some senators have complained that Gen Clapper is too closely aligned to the military, while others have questioned whether he has the force of personality to bring the sprawling US intelligence system under his control.
Politicians from both parties have claimed that Gen Clapper has sometimes been combative and obstructive under questioning on Capitol Hill.
But supporters have pointed to his long experience and extensive knowledge of the intelligence community.
During his military career, Gen Clapper attended the US Air Force's Signal Intelligence Officers Course, before serving in Vietnam and later in South Korea.
In his last job before retiring he was director of the Defense Intelligence Agency from 1991 to 1995.
The body has strong links with the Central Intelligence Agency (CIA) and Gen Clapper is reputed to be particularly close to CIA senior managers.
After leaving the US Air Force, he worked for six years in the private sector, for companies including Vredenburg, Booz Allen Hamilton and SRA International.