The hellenistic culture that developed after alexander the great died was influenced by the cultural exchange between greeks and conquered peoples

no every country is held to the same degree as others just some member countries such as the usa and germany are more economically sound so the need to show there support to all others  

geography

this is because warmer climates often don't get people sick from the flu and regions where it was often colder more people received the flu. hope this if you need more reasoning i am here to