In his latest speech addressed to the people of the United States (see here for the transcript), Osama bin Laden invites us "to embrace Islam, for the greatest mistake one can make in this world and which is uncorrectable is to die while not surrenduring to Allah, the Most High, in all aspects of one's life - i.e., to die outside Islam. And Islam means gain for you in this first life and the next, final life."
No thanks Mr. bin Laden. I already gave up one delusion, the belief in the god of the Christians. I am not going to embrace your delusion.
Instead, I call on you Osama bin Laden, to embrace secular humanism, accept responsibility for your role in multiple terrorist attacks that caused the deaths of thousands of innocent civilians, and to surrender yourself to the nearest United States or allied military post in Afghanistan to stand trial for your crimes.
As for the people of the United States converting en masse to Islam, it still would not solve the problem of American military intervention in the Middle East. Our economy would still be dependent on oil, thus necessitating our having an active presence in the region. The Islamic world has not been united since the days of the Ummayad Caliphate in the 7th century C.E., and it is a fantasy that a worldwide Islamic caliphate will ever arise where Muslims of all races and nationalities will live together in peaceful brotherhood. If history tells us anything, it tells us that humans will always find reasons to live in strife with one another, and nothing is likely to ever change that, including a worldwide embrace of Islam.