The articles of confederation had no blank sys

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).