The U.S. Embassy in Tokyo has seen its share of luminaries in the ambassador's suite. Former Vice President Walter Mondale, former Senate Majority Leaders Mike Mansfield and Howard Baker and former House Speaker Tom Foley are among those who have brokered relations with a complex and critical ally in a region bristling with military and trade tensions.

President Barack Obama's pick for the post is from a different mold: John Roos, a San Francisco Bay area lawyer, was the president's chief Silicon Valley fundraiser and contributions "bundler." He has no diplomatic experience.

Mr. Obama's choice of Mr. Roos, along with other political boosters -- from former investment banker Louis B. Susman, known as the "vacuum cleaner" for his fundraising prowess, to Pittsburgh Steelers owner Dan Rooney -- has raised eyebrows among some who thought the president would extend his mantra of change to the diplomatic corps.

"We're not only insulting nations [that] we're appointing these bundlers to, we're risking U.S. diplomatic efforts in these key countries," said Craig Holman, a government-affairs lobbyist at watchdog group Public Citizen.

This tension can be traced back to Mr. Obama's claim during last year's campaign that President George W. Bush engaged in an "extraordinary politicization of foreign policy." Mr. Obama said he instead would ensure that hires are based on merit, rather than party or ideology. The American Academy of Diplomacy, an association of former diplomats, seized on the comments in lobbying him to lower the portion of ambassadors drawn from outside the foreign-service establishment to as little as 10% from the 30% average since President John F. Kennedy's tenure. (Mr. Bush's score was 33%.)