Answer:
Alliance System
Explanation:
If you look closely in the cartoon, you see that Austria, Germany, and Russia are all touching their shoulders to try and beat Serbia. This means that they are supporting each other and are allies, which is the definition of an alliance system.
Militarism, the belief of a strong military; imperialism, extending a country's power, and Nationalism which is the belief of being proud for a country are all historical terms but not relevant.
