to serve their country? to have money? this is a blanket question i can try to answer it if you give me more detail.
Answer:
The Nations in it
Explanation:
First of all, the triple alliance was an alliance made up of Austria Hungary, Germany, and Italy, but this was a defensive pact. So when Austria Hungary caused world war 1, Italy didn't join because Austria Hungary was acting like the aggressor, and later on Italy joined the allies against Germany and it's allies, so that's one of the weaknesses. This then left Germany and Austria-Hungary together, but the thing though was that Austria-Hungary was a super multiethnic empire and had too many revolts and uprisings, so this only left Germany, which was the only empire who performed well in the war, and that's another weakness.