In OTL's Second Balkan War in 1913, Romania conquered Bulgarian ruled Dobruja, and retained it until WWII when Bulgaria won it back permanently.
In OTL, the Romanians were taking over a territory they were interested in and taking advantage of circumstances where the Bulgarians had recently aggrandized themselves but also turned on their allies.
What if Romania sought this territory earlier?
There seem to be two times when the situation could have been somewhat comparable.
Romania could have moved to attack Bulgaria in the back upon the commencement of the first Balkan War against the Ottomans. Whether or not it helps the Turks, the Turks would be pleased with it. The Austrians might also be pleased. I am not sure the Russians would be displeased to a level dangerous to the Romanians.
An earlier scenario could be if Romania attacks Bulgaria when it declares independence in 1908. At this time, there is not a similar military distraction for the Bulgarians, but the Bulgarians also do not have their alliance with the Serbs and Greeks yet.
In OTL, the Romanians were taking over a territory they were interested in and taking advantage of circumstances where the Bulgarians had recently aggrandized themselves but also turned on their allies.
What if Romania sought this territory earlier?
There seem to be two times when the situation could have been somewhat comparable.
Romania could have moved to attack Bulgaria in the back upon the commencement of the first Balkan War against the Ottomans. Whether or not it helps the Turks, the Turks would be pleased with it. The Austrians might also be pleased. I am not sure the Russians would be displeased to a level dangerous to the Romanians.
An earlier scenario could be if Romania attacks Bulgaria when it declares independence in 1908. At this time, there is not a similar military distraction for the Bulgarians, but the Bulgarians also do not have their alliance with the Serbs and Greeks yet.