Rumania As A Causus Bellum In 1912

[wkwillis]

The proGerman king of Rumania gets bumped off and Rumania joins the Serbs in opposing Austria-Hungary. Franz-Ferdinand still alive. The First Balkan war is still going on, with Constantinople under siege.
So who attacks whom, and why?
Britain wants the Straits closed to Russia. Russia wants the Straits open or at least closed to everybody. What about giving the Russians a base on an island in the Sea of Marmara? Who is going to try and get by 1,000 Russian torpedo boats and a few dozen subs?
Is this acceptable to Austria-Hungary?

 

[Andrei]

What about this:

-king Charles I of Romania dies in 1910 , 4 years earlier than in OTL
-he is succeded by Ferdinand I ( Romania's king at the time the Romanians attacked Austria-Hungary)
-relations between Romania and A-H chill due to the problem of the Romanians living in A-H ( Transilvania )
-Romania and Serbia sign a mutual protection pact
-the 2nd Balkan war goes on schedule
-Greeks occupy Thessaloniki
-with the support of A-H , an Albanian state is created from the former Ottoman territory it should have gone to the Serbians ( as in OTL )
- The Serbians refuse to evacuate the territory of modern-day FYR Macedonia , that should have gone to the Bulgarians ( as in OTL )
- A-H supports Bulgaria because she wants a strong ally in the Balkans to counter Serbia and Romania. The Bulgarians are persuaded by the A-H to give back to the Ottomans some territories in Eastern Thrace but they are encouraged to attack Serbia and Greece
-Bulgaria declares war on Greece and Serbia
-Montenegro declares war on Bulgaria
-The Ottomans stay neutral
-A-H declares war on Serbia , Greece and Montenegro
-Belgrade is bombed by A-H artillery
-Romania declares war on A-H
-Bulgaria declares war on Romania

Now , this could end in 3 ways:

1) The Great Powers step in and mediate a peace treaty
2) The warring states are left to fight ( maybe Italy attacks A-H in this case )
3) -Russia mobilises to help Serbia
-Germany demands the Russians to stop the mobilisation
-Russia refuses
-Germany and A-H declare war on Russia
-Germany declares war on France and invades Belgium
-Britain declares war on Germany
-The Ottoman empire joins the Central Powers

 

[Wendell]

Suppose Russia jumped sides, or France and Britain stand down. I think this would change the circumstances enough to prevent German involvement, or to avoid a wider war in the west.....