Pablo Picasso's Guernica was a portrayal of a bombing during the Spanish Civil War and it's fame brought a lot of attention to the horrors of the war on the part of the Spanish Nationalists.
Answer:
Because a ideas might be opposite or oppose one another
Explanation:
Like the american civil war. Where the north fought the south to free the slaves. The north does not like slavery while the south likes slavery.
Your answer is, countries that were fighting against Communism.