Theonewhoknows

Actually it's quite simple, you're all giving this thing to wrong targets. For it to be undetectable, speed of the end term effect would make it very obvious that "something is out there that has been created by someone to kill us". The worst weapons are always the most subtle ones. what you would ideally want to create is a gene specific bio weapon in the form of a virus (preferably airbourne) that would not endanger the life in question of the target, but their ability to reproduce and if they manage to reproduce there would be a high chance that children born to these people would carry the virus and therefore the effects would unfold quite under the radar for a period in time in which the "attacking" country would do well to pump MASSIVE amounts of capitol into ICBM shields which, when eventually found out, would be impossible to retaliate against due to the only viable threat of retaliation (nuclear weapons) would be negated. As time would go on, the enemy population would grow older and lose an exponential amount of manpower over the years. There you go. Horrible stuff I'm postulating on though.