Any empire becomes nervous when another empire is established, especially when the new empire borders its own.
This is doubly true when some components of the new empire were formerly part of the old one.
Austria-Hungary, Mentenegro, and Serbia
Austria-Hungary's future king was assassinated.
Austria-Hungary
Serbia
Serbia
they promised to support Austria-Hungary after it threatened to invade Serbia
Germany guaranteed Austria-Hungary its support in the conflict with Serbia.
Answer this question… Russia had an alliance with Serbia, and Germany had an alliance with Austria-Hungary.
they promised to support Austria-Hungary after it threatened to invade Serbia
Austria-Hungary feared Serbia because of the growing size of Serbia and because of Serbia existing as a free national state Hope this helps!
Austria-hungary attacked Serbia
Russia