Answer:
Nationalism helped unite citizens within a certain group(such as common culture or history). However, it can also cause intense competition between nations. Many ethnic groups part of the Ottoman empire wanted to become independent and were successful going about these ways, which divided them.
How did Winston Churchill's "Iron Curtain" speech impact the Truman Doctrine? Churchill's famous speech convinced many Americans that the USSR was an enemy rather than an ally, which led to the creation of the Truman Doctrine. ... The USSR needed to protect its western border from future attacks.
<u>Germanic tribes</u> -- especially the <u>Visigoths</u> -- attacked the Roman empire and caused it to weaken.
There had been ongoing migration of Germanic tribes into Roman empire territory, that had a gradual weakening effect on the empire. The western tribes consisted of groups such as the Alamanni, Franks, Angles, and Saxons. There was also a large group of Germanic tribes known as the Goths. We speak of the Visigoths and Ostrogoths do distinguish between the western and eastern Goths. The Visigoths (western Goths) invaded the Roman Empire, and defeated Roman armies at the Battle of Adrianople in 378. Later, the Visigoths even invaded Italy and sacked the city of Rome in 410. So I suspect the answer your question is primarily looking for is the Visigoths.
