The C.I.A. has spent five years trying to overthrow Saddam Hussein -- not an easy task against a brutal dictator who rules by killing all his opponents. Barred in 1976 from assassinating anyone, the agency has been trying to foment a coup.

It is not the first time the C.I.A. has meddled in Iraq. In the early 1960's its gruesomely named ''health alteration committee'' sent a monogrammed, poisoned handkerchief to Gen. Abdel Karim Kassem, Iraq's leader. The handkerchief either didn't work or wasn't used. In any case, an Iraqi firing squad executed Kassem in 1963, paving the way for Saddam Hussein's rise to power.

From 1972 until 1975, when the Nixon Administration pulled the rug out, the C.I.A. supported the Kurds against Iraq to assist Iran. It was a cynical enterprise; a 1974 agency memo said that the purpose was to create a stalemate to tie up Iraq's military. ''Neither $(Iran$) nor ourselves wish to see the matter resolved one way or the other,'' the memo said. Only nobody told the Kurds.

Proponents of covert operations usually justify them on the grounds that a President needs an option somewhere between diplomacy and war. They also say that it is impossible to monitor elusive terrorist groups without infiltrating them. For the most part, however, the C.I.A.'s covert actions have been counterproductive. By interfering with the internal affairs of other countries, these operations violate international law and the United Nations Charter. And in an age when world leaders get their information from CNN, covert operations are rarely covert for very long.

Even the agency's ''successes'' have been failures. In Iran, the C.I.A. restored the Shah to the throne in 1953. But this planted the seeds of discontent that led to the Islamic revolution and the hostage crisis in 1979.