The concept of genocide carries a lot of weight in international law. The 1948 U.N. convention on genocide requires signatories to work to prevent genocide and punish perpetrators when it does occur.
However, while the United Nations defines the term as "acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group," it does not cover systematic violence against a particular sex. And according to one French lawmaker, the violence being committed by the Islamic State against women is so systematic and so ferocious that it needs a new term in international law to define it: femicide."
Read article by Adam Taylor from The Washington Post.