<<How could they "payback"?
<<The reason we are intrested in makeing them extinct is because they are building WMD , and painting a target on our forheads.>>
I think you'd better make up your mind whether you are afraid of them or not. If there is nothing to fear from them, you don't have to fuck with them and if they scare you enough to fuck with them, you'd better figure out fast that you don't get rid of 70 million people all that fast and that no matter what your first strike does, there will be plenty of them left to figure out their payback, planning for which is probably well underway now.