The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, nationalism) was the assassination of Archduke Franz Ferdinand of Austria Hungary.
Answer:
Local collaborators
Explanation:
Germany had a large, strong, well trained, and well equipped army, but that still was not enough so that they can be all over Europe and control everything themselves. In order to be able to keep things under control and their goals to be achieved, the Germans depended a lot on local collaborators. Some of those collaborators were from the occupied countries, while some were smaller countries that had allied with the Germans. Some of the countries that were helping the Germans in their goals were the Hungarians, Bulgarians, Lithuanians, Italians, Albanians, Croatians. All of them were managing to keep control with their military forces on local level, which was easing things up a lot for the Germans to make further expansion and get involved into some battles.
