Hughes' performance drew mixed reviews in the Muslim world. She got credit for hard work and frequent travel but was prone to gaffes such as vastly overstating Saddam Hussein's use of poison gas against his people before he was deposed by a U.S.-led invasion in 2003.
Hughes said the Iraq war was usually the second issue that Muslims and Arabs raised with her, after the long-standing conflict between Israel and the Palestinians. Hughes said she advised Bush and Rice two years ago that U.S. help in ending the six-decade old fight over Israel would probably do more than anything else to improve the U.S. standing worldwide.
Hughes said she told Bush and Rice over the summer that she did not plan to stay through the end of Bush's term, which ends in January 2009. Rice, who has also worked for Bush since he was a presidential candidate eight years ago, has announced no plans to leave.
This is Hughes' second departure. She was among Bush's closest confidantes during his first term before leaving the White House in 2002. She never fully left Bush's employ, serving as an offsite strategist and adviser until she returned to Washington to take the State Department job in 2005.
Hughes had been splitting her time between Texas and Washington.
She worked with Bush since the 1990s, first as director of communications while he was governor of Texas, from 1995 to 2000.