As the first female national security adviser, Rice developed by most accounts a strong working relationship with Bush. And she demonstrated unwavering support for Bush's decision to wage war in Iraq while earning nicknames such as "warrior princess."
The tenure of her predecessor, Secretary of State Colin Powell, was marked by clashes with the Pentagon over issues such as Iraq. But experts expect Rice to pursue policies more in keeping with the rest of the administration.
That could spell bad news for some European allies. Relations have been tense due to the Iraq war, but Germany and France have long seen Powell as a moderating influence over administration hard-liners.
But analyst Antonio Missiroli of the Paris-based European Union Institute for Security Studies believes that a Bush administration that speaks with a more unified voice could have a positive influence on the trans-Atlantic relationship.
"If Condi Rice will bring a more unitary view on the part of the U.S. administration, that would be, I suppose, welcome from the Europeans' [point of view], because it will create a basis for real negotiations with the administration -- one person in charge of the U.S. [diplomatic] language," Missiroli said.
Still, critics have misgivings about Rice.
They say she unsuccessfully managed the policy conflicts of the first administration, such as those pitting Powell against Defense Secretary Donald Rumsfeld.
Perhaps ironically, Rice had pledged to work for the unity of the Bush team following her nomination in December 2000.
"He (George W. Bush) will have an administration that is inclusive, an administration that is bipartisan, and, perhaps most importantly, an administration that affirms that united we stand, divided we fall," Rice said at the time. "And I'm very proud to have a chance to be a part of it."
Despite her tough appearance, Rice, who turned 50 on 14 November, is considered a brilliant intellectual, a talented artist, and an accomplished athlete.
Rice was born in the city most notorious for racial segregation -- Birmingham, Alabama.
The daughter of a music teacher and a pastor who was also a school principal, Rice was taught that only through education could she escape racial prejudice.
She studied to become a classical pianist and ice skater and was only 19 when she graduated from college. Rice later gave up music and devoted herself to the study of international relations after being inspired by a course taught by Czech refugee Josef Korbel -- the father of Madeleine Albright.
The first female secretary of state, Albright preceded Powell and served under former President Bill Clinton.
Fluent in Russian, Rice served for two years as the National Security Council's Soviet expert just as communism was collapsing during the administration of Bush's father.
Rice went on to become George W. Bush's tutor on foreign affairs during the 2000 election campaign.
Their bond grew after Bush became president. Rice has since spent a lot of time at the president's side, forging a relationship that some say has transcended her position as national security adviser.
Meanwhile, analysts believe Rice's expertise on Russia could spark a change in U.S. attitude toward Moscow, one that could bring U.S. and Western Europe closer together. Italian-born analyst Missiroli explains why.
"The main focus of Condi Rice's expertise is notoriously Russia and that could be interesting for Europeans, because that is an issue on which perhaps some better cooperation between the United States and the Europeans -- especially in those areas starting with Ukraine and the South Caucasus, where some tension is lingering between East and West again -- could be extremely useful," Missiroli said.
In an ironic example that others have made, "The Los Angeles Times" wrote today that as Bush's adviser in 2000, Rice argued that "the United States should accept other nations as it found them -- and avoid overly ambitious crusades to reform nations with different histories and cultures."
But now, the newspaper noted, Rice has moved "closer to the views generally considered part of neo-conservative thinking."
Such thinking was the chief inspiration behind the Iraq war and the idea that the United States must bring freedom and democracy to the Muslim world in order to win the war on terrorism and prevent attacks on America.
Earlier this year, an independent panel investigating the 11 September 2001 attacks on the United States harshly criticized Rice for not reacting to repeated warnings in 2001 about the possibility of a major terrorist attack.
Such criticism is likely to resurface during Rice's confirmation hearings in the Senate. But Rice, speaking to the "9/11" commission last April, said information about such an attack had not been sufficient:
"There was no silver bullet that could have prevented the 9/11 attacks," Rice said. "In hindsight, if anything might have helped stop 9/11, it would have been better information about threats inside the United States, something made difficult by structural and legal impediments that prevented the collection and sharing of information by our law enforcement and intelligence agencies."
Rice is likely to remain focused on Iraq and national security during the next four years.
But as the British daily "The Guardian" noted today, other issues appear likely to demand the attention of America's next top diplomat.
Iran and North Korea -- to name just two countries of concern -- look set to present Rice with her next major challenges.