Brilliantlight said:
Could Austria-Hungry last a longer time? Would WWI be avoided or merely delayed? Who would be strengthend and who weakened compared to OTL?
I think the annexation did the following negative things:
1. Upset the careful ethnic balances of the Hapsburg state
2. Poisoned the relationship with Hungary, suspicious of the Hapsburg's motives
3. Poisoned the relationship between A-H and Russia
4. Radicalized Serbia & Montenegro & made conflict with them inevitable
5. Made South Slav nationalism incompatible with the existance of the Hapsburg State.
6. Made the Balkan Wars nearly inevitable and thus WWI.
If B-H had been left alone, the Balkans might have remained a bit more stable. Austria would be between Serbia & Montenegro (when B-H was annexed, Novi Pazar was returned to Ottoman administration), and the Balkans would have been less encouraged to make land grabs - the CUP government in Istanbul probably would not have lasted and thus their foolish foreign policy would have destabilized the Balkans further.