I don't think OBL became an 'official enemy' of the USA until the mid-1990s, by which time he'd moved to Sudan, and apparently what set him off was infidel US s

I don't think OBL became an 'official enemy' of the USA until the mid-1990s, by which time he'd moved to Sudan, and apparently what set him off was infidel US soldiers on holy Saudi land during the Gulf War II (I being the Iraq-Iran war of the 1980s). BCCI had mostly been dissolved by then, although some remnants and associates then went on to become 'Al Qaeda's Bank'.