Clinton explained that the U.S. always insisted on bringing Bergdahl home if they were to free Guantanamo detainees sought by the Taliban.
"The Taliban's top concern seemed to be the fate of its fighters being held at Guantanamo Bay and other prisons. In every discussion about prisoners, we demanded the release of Army Sergeant Bowe Bergdahl, who had been captured in 2009. There would not be any agreement about prisoners without the sergeant coming home," she wrote.
Read more excerpts from Clinton's book here.
The publisher of Clinton's book, Simon & Schuster, is owned by CBS.