Speculation is growing that Gen. Jim Jones will not last long as President Obama's national security adviser because of the retired Marine general's supposedly poor performance.
Several White House and National Security Council sources told FOX News that the Obama administration is baffled by Jones, who is a longtime friend of Sen. John McCain, the man Obama defeated for the White House. One NSC staff member claimed that Jones is so forgetful that at times he appears to have Alzheimer's disease.
Jones' primary duty is to manage the conflicting views of the State Department, Pentagon and other parts of U.S. foreign policy. But he isn't seen near Obama's side often and he has kept his distance from the media.
Obama officials don't expect Jones to stay in his post past the fall, one source told FOX News.
But Secretary of Defense Robert Gates took the unusual step this week of reaching out to the Washington Post to defend Jones and dismiss the rumors.
Gates told Washington Post columnist David Ignatius that the rumors are coming from "lower levels," not from any of the power brokers.
"If nobody's fighting, nobody's having fun," he said.
He admitted generational differences exist between the White House and the foreign policy makers, but added that he doesn't sense "antagonism" or "jealousy."
"Jim and (Secretary of State) Hillary (Clinton) and I have joked with each other that we're of a different generation than those in the White House," Gates said. "While they're texting, we're on the cell phone or even a land line."
Gates said Jones is "among the best" national security advisers he's seen and described him as "the glue that holds this team together" and as an "honest broker."
"I can trust Jim to represent my views on an issue to the president," he said. "He is a facilitator, not an obstacle, and that hasn't always been true in that job."
FOX News' Jennifer Griffin contributed to this report.