because big countries and Russia and U.S.A are killing Muslim people for a several years and destroying their houses, many of innocent people were killed and now tortured people are trying to repay for this.
Russia and the US are not sending their troops to the Muslim nations to kill them. The Muslims are killing each other without the silliest of the provocations. You can't put the blame on US/Russia, when you don't have the minimum commonsense to stay away from fighting.
