Which military alliance of north american and western european nations pledged in 1949 that all member nations would come to the aid of any member attacked by an outside enemy?

45

Explanation:

bc why not

the correct answer is =   british soldiers attacked and killed five boston townspeople.

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).