- Ideology: The Spanish Civil War was seen as a battle between fascism and communism. The war became symbolic of a wider struggle between different political ideologies.
- Involvement of foreign powers: The Spanish Civil War saw large scale direct and indirect military intervention by foreign powers. This included the deployment of troops from Germany, Italy, the Soviet Union, and Mexico, as well as large quantities of weaponry. The use of new weapons and tactics gave the war an element of novelty that attracted much attention.
- Humanitarian crisis: The Spanish Civil War was incredibly destructive and caused a great deal of human suffering. The war resulted in over half a million deaths, the displacement of millions of people, and the creation of refugee camps. The suffering of civilians and the atrocities committed by both sides were widely reported and contributed to the international attention the war received.
- Cultural significance: Spain was a major European cultural centre, and many prominent intellectuals, artists, and writers expressed support for one side or the other in the war. The political and cultural allegiances of these figures helped to bring international attention to the conflict.