Bin Laden's grudges against the "western world". In 1996, Bin Laden declared war on America, and issued the declaration that you see below that I have copypasted from another place on the web (readily available).
Bin Laden, in his 1996 fatwa (declaration) entitled "Declaration of War against the Americans Occupying the Land of the Two Holy Places," identified several grievances that he has about Saudi Arabia, the birthplace and holy land of Islam. (and I quote directly from the fatwa):
"(1) The intimidation and harassment suffered by the leaders of the society, the scholars, heads of tribes, merchants, academic teachers and other eminent individuals;
(2) The situation of the law within the country and the arbitrary declaration of what is Halal and Haram (lawful and unlawful) regardless of the Shari'ah as instituted by Allah;
(3) The state of the press and the media which became a tool of truth-hiding and misinformation;
(4) Abuse and confiscation of human rights;
(5) The financial and the economical situation of the country and the frightening future in the view of the enormous amount of debts and interest owed by the government;
(6) The miserable situation of the social services and infra-structure especially the water service and supply , the basic requirement of life.,
(7) The state of the ill-trained and ill-prepared army and the impotence of its commander in chief despite the incredible amount of money that has been spent on the army. The gulf war clearly exposed the situation.,
(8) Shari'a law was suspended and man made law was used instead.,
(9) And as far as the foreign policy is concerned the report exposed not only how this policy has disregarded the Islamic issues and ignored the Muslims, but also how help and support were provided to the enemy against the Muslims; the cases of Gaza-Ariha and the communist in the south of Yemen are still fresh in the memory, and more can be said."