The way the U.S. assisted the 1963 Iraqi coup by Saddam Hussein's Ba'ath Party was financially. Writing in his memoirs of the 1963 coup, long time OSS and CIA intelligence analyst Harry Rositzke presented it as an example of one on which they had good intelligence in contrast to others that caught the agency by surprise. The Ba’ath overthrow “was forecast in exact detail by CIA agents.”
"Agents in the Ba’th Party headquarters in Baghdad had for years kept Washington au courant on the party’s personnel and organization, its secret communications and sources of funds, and its penetrations of military and civilian hierarchies in several countries…
CIA sources were in a perfect position to follow each step of Ba’th preparations for the Iraqi coup, which focused on making contacts with military and civilian leaders in Baghdad. The CIA’s major source, in an ideal catbird seat, reported the exact time of the coup and provided a list of the new cabinet members.
…To call an upcoming coup requires the CIA to have sources within the group of plotters. Yet, from a diplomatic point of view, having secret contacts with plotters implies at least unofficial complicity in the plot."
“Unofficial complicity in the plot” indeed. The CIA would have paid a lot of money for this steady supply of information, especially because American planners had determined that the Ba’ath Party would be the best for U.S. policy in Iraq going forward in 1962. The First Political Secretary of the U.S. Embassy in Iraq in 1963 during the coup, Bill Lakeland, has admitted that CIA officer Ed Kane told him that the U.S. “had people who informed us about things…The CIA was kept aware of what was happening…[The CIA] had paid informants within the Ba’ath, but had no control of any operational…It was ultra secret….” Ed Kane was in charge of the Iraq Desk in Washington at the time of the coup.
The best direct evidence that the U.S. was complicit is the memo from NSC staff member Bob Komer to President John F. Kennedy on the night of the coup, February 8, 1963. The last paragraph reads,
"We will make informal friendly noises as soon as we can find out whom to talk with, and ought to recognize as soon as we’re sure these guys are firmly in the saddle. ________excellent reports on the plotting, but I doubt either they or UK should claim much credit for it."
Eight typewritten spaces are still classified just before the word “excellent.” “CIA had,” would fit in here perfectly and is most likely in the original. This is consistent with Rositzke’s memoir that writes of the CIA having a “major source in an ideal catbird seat.” They would have had to pay money for this, but probably did not do too much more than fund the coup and this is why Komer wrote, “I doubt whether they [CIA] or UK [British Intelligence] should claim much credit for it.” They can claim some but not much credit for it. At least they helped fund it and gave assurances that the Ba’ath would be well received in Washington and as CIA analyst Harry Rositzke stated, they were "complicit in the plot."
 See Harry Rositzke, The CIA’s Secret Operations: Espionage, Counterespionage, and Covert Action (Boulder, CO: 1977), 109-110.
 United States, Department of State, Nina J. Noring and Glenn W. LaFantasie eds. Foreign Relations of the United States, 1961-1963, vol. XVII: Near East 1961-1962, 364-365.
 Interview with Lakeland, June 2005.
 Interview with Kane, June 2005.
 Kennedy Library, “Secret Memorandum for the President: R. W. Komer to Kennedy,” National Security Files, Countries, Box no. 117, Iraq 1/63-2/63, originally partially published in United States, Department of State, Nina J. Noring and Glenn W. LaFantasie, ed. Foreign Relations of the United States, 1961-1963, vol. 18: Near East 1962-1963, 334n-335n.