Condoleezza Rice is the first woman to occupy the key post of national security adviser.

She is the most academic member of the Bush foreign affairs team and - because of her gender, background and youth - one of the most distinctive.

She is personally close to Mr Bush, barely leaving his side during the 2000 presidential election.

And, as a well-liked and trusted policy adviser, she has proved a useful ally for a president with little experience of foreign affairs.

Past advisers

The profile of the national security adviser varies from one administration to the next, as does their power over policy.

Some, like Ms Rice's mentor (and national security adviser to George Bush Snr), Brent Scowcroft, were important, but low-profile co-ordinators of foreign policy.

Others, such as Bill Clinton's Sandy Berger, were more visible.

Perhaps the most powerful and visible national security adviser of recent years was Henry Kissinger, who started as national security adviser to Richard Nixon and then became his secretary of state.

Uncompromising positions

Ms Rice's influence over the new administration's early foreign policy strategy has been considerable.

She led the tricky negotiations with Russia (her academic specialisation) over missile defence, and is thought to have spearheaded the unilateralist tone of the first months of the Bush presidency.

Her uncompromising positions on missile defence, Russia and the environment won respect but helped build the European caricature of the new president as toxic troglodyte.

She has since admitted that the Kyoto decision could have been handled better.

However, Ms Rice, like many in the administration, thinks of US foreign policy largely in terms of US national and strategic interest, and she is no fan of the US acting as a paternalistic nation-builder.

Against the odds

Ms Rice was born in 1954 and grew up in Birmingham, Alabama under the shadow of segregation.

She has often said that to get ahead she had to be "twice as good" and her childhood chiselled her strong determination and self-respect.

Taught by her parents that education provided armour against segregation and prejudice, Ms Rice worked her way to college by the age of 15.

She graduated at 19 from the University of Denver with a degree in political science.

Soviet interest

It was at Denver that Ms Rice first became interested in international relations and the study of the Soviet Union.

Her inspiration came from a course taught by the Czech refugee, Josef Korbel, father to the United States' first woman Secretary of State, Madeleine Albright.

A masters and doctorate followed and, at the age of 26, Ms Rice became a fellow at Stanford University's Centre for International Security and Arms Control.

After serving as the Soviet affairs adviser on Bush Senior's National Security Council, Condoleezza Rice returned to Stanford in 1991 and, in 1993, became the youngest, the first female and first non-white provost.

It is difficult to make generalisations about Condoleezza Rice. She is an African-American National Security Adviser, but for a Republican administration that won just 10% of the black vote.

Some profiles of Rice describe her as precise and prissy. But she is also a pianist, ice skater and sports fan.

Rice's belief in education and self-improvement seem to be the key to understanding her.

In an interview with Newsweek magazine, Rice said that despite growing up with racial segregation, personal expectations were high.

"My parents had me absolutely convinced that, well, you may not be able to have a hamburger at Woolworth's but you can be president of the United States."