According to Buddhism, individuals are masters of their own destiny. And all living beings are believed to possess the nature of the Primordial Buddha Samantabhadra, the potential or seed of enlightenment, within them. So our future is in our own hands. What greater free will do we need?
The Buddhist tenet, "Non-killing is supreme virtue", is very good, but in trying to enforce it upon all by legislation without paying any heed to the capacities of the people at large, Buddhism has brought ruin upon India.
Americans are interested because they are open-minded. They have an education system that teaches them to find out for themselves why things are the way they are. Open-minded people tend to be interested in Buddhism because Buddha urged people to investigate things - he didn't just command them to believe.