Rice previously served in various national security positions in former US president Bill Clinton’s administration, including key roles on peacekeeping and African affairs.
Her world view is said to have been shaped by Clinton’s decision to not intervene in the Rwandan genocide, a move Rice said later deeply affected her.
Power, a human rights advocate and genocide expert, was among the fiercest critics of Clinton officials, including Rice, who kept the US out of Rwanda.
Power served as an informal adviser to Obama’s 2008 presidential campaign, but resigned after calling then-rival Hillary Rodham Clinton a “monster.”
She later joined Obama’s national security staff at the White House, overseeing the human rights portfolio.
Despite their reputations as interventionists on humanitarian grounds, neither Rice nor Power has staked out a public position on Syria that differs from the president’s.