Unfortunately, there is little difference in practice. When Israel is singled out for condemnation for practices no worse than those of other countries who escape condemnation, there is no other word for this than antisemitism.
Admiteddly there is an extraoridnary overlap in those who are both antisemitic and anti-Israel. However just as it is possible to be against American policies without disliking Americans, it is clearly possible to be against Israeli policies without inherent dislike or hatred of Jews.
This article seems to indicate that Germans confuse these things. My experience says they do not.