Ellie,
You have asked one of those imponderable questions about God that theologians of all religions have been debating for centuries, and not just JW's.
We are talking about the "Foreknowledge" of God. If God is all powerful, and knows the beginning from the finale, does this mean that God caused it all to happen? Or does it mean that God would let everything happen, but because He is God, He would simply be able to predict from His Perfect Foreknowledge that such and such "Will Happen".
To use a crude analogy, if you saw your small child playing with matches, you would pretty well have the foreknowledge that your child would burn himself/herself if he/she lit them and put their fingers in the flame. This does not mean you forced your child to play with matches, just that, knowing your child, if there were matches there, he/she would be naturally curious enough to play with them, and from there you could see the consequences, while your child could not.
God knows all of us and the entire Universe infinitely more, since He created it all. Therefore he would know and see much deeper and farther than any of us mere mortals. But this does not prove that God caused us to behave a certain way; just that He would know that we would act a certain way, which would produce the natural consequences, which He would also know.
On the other hand, if God created us with the Nature that we have, and we do bad things or make bad or dangerous choices, does that not make God responsible for everything that happens in the Universe? If we weren't the way we were, then we wouldn't choose the way we do, and so the consequences would be different.
Rod P.