From a December 1998 interview with Osama bin Laden:
TIME: The U.S. says you are trying to acquire chemical and nuclear weapons. How would you use these?
bin Laden: ‘Acquiring weapons for the defense of Muslims is a religious duty. If I have indeed acquired these weapons, then I thank God for enabling me to do so. And if I seek to acquire these weapons, I am carrying out a duty. It would be a sin for Muslims not to try to possess the weapons that would prevent the infidels from inflicting harm on Muslims.’ “
[The 15th of the month used for date sorting purposes only.]

 – Rahimullah Yusufzai, “Osama bin Laden: Conversation With Terror,” Time, Jan. 11, 1999