American Notes WASHINGTON

"This incident proves you can't tell Congress anything without it leaking," said a senior White House aide last week, after the Washington Post reported that President Reagan had authorized unspecified covert action to help oust Panamanian Leader Manuel Antonio Noriega. Not so, said both Democrat David Boren, chairman of the Senate Intelligence Committee, and ranking Republican William Cohen. The two Senators got questions from reporters even before the committee was briefed on the finding. That, they charged, meant the Administration had divulged the information to "set up" the committee as being unable to keep secrets.

Editors at the newspaper, alerted to the Capitol Hill briefing, said they smoked the story out of sources in both branches of Government. A more probable motive for the leak: to convince Noriega's Panamanian foes that they have not been abandoned by the U.S.