According to statements made by former CIA Director Admiral Stansfield Turner in 1988, Noriega was on the CIA payroll since the early 1970s and he retained U.S. support until February 5, 1988 when the DEA had him indicted on federal drug charges relating to his activities before 1984. On February 25, Delvalle issued a decree, declaring that Noriega was relieved of his duties. Noriega ignored the decree, which he claims had no legal basis, and Delvalle left for the U.S. Noriega claims that on March 18, 1988, he met with U.S. State Department officials William Walker and Michael Kozak, who offered him $2 Million to go into exile in Spain. According to Noriega, he refused the offer.
Sen. John Kerry's 1988 Subcommittee on terrorism, narcotics and international operations concluded that "the saga of Panama's General Manuel Antonio Noriega represents one of the most serious foreign policy failures for the United States. Throughout the 1970's and the 1980's, Noriega was able to manipulate U.S. policy toward his country, while skillfully accumulating near-absolute power in Panama. It is clear that each U.S. government agency which had a relationship with Noriega turned a blind eye to his corruption and drug dealing, even as he was emerging as a key player on behalf of the Medellin cartel {among whom Pablo Escobar}." Manuel Noriega was allowed to establish "the hemisphere's first 'narcokleptocracy'".
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...US President George H. W. Bush launched Operation Just Cause, though this military action had obviously been planned out months in advance. This move was thought by some critics to be ironic since, during his tenure as Director of the CIA, George H. W. Bush had personally arranged annual payments to General Noriega in the initial amount of $110,000 - (as noted in the House Foreign Affairs Committee Report: "Narcotics Review in Central America" - U.S. Govt Printing Office, 1988). Losses on the U.S. side were 23 troops, plus three civilian casualties. The U.S. claimed Panamanian losses were "several hundred," though exact statistics remain disputed, and some Latin American and international sources have estimated the civilian death toll may have been as high as 3,000 to 5,000. The conflict also caused some considerable domestic problems, with 20,000 to 30,000 having been rendered homeless. Probably the majority of those resulted from a fire that devastated much of a poor area of Panama City that surrounded the Comandancia, a fortified headquarters that was shelled.
See more at:
http://en.wikipedia.org/wiki/Noriega