Why hasn't Israel signed the Biological and Toxin Weapons Convention?

Because the land (uterus) of Israel (It really doesn't matter if you call it Palestine either), being the slut that it has been over the years suffers from an STD called religion, and it realizes the only way it can survive and propagate is to spread its disease by having unprotected *sex*. The BTWC represents a contraceptive it is not prepared to use.