Second Balkan War, Romania joined Greece, Serbia and Montenegro against Bulgaria. In the Treaty of Bucharest of 1913, Romania gained Southern Dobruja and established the Durostor and Caliacra counties. The governments of Britain and the United States repeatedly protested the brutal treatment of Romanian Jews, who were regarded as aliens who had no civil or political rights. The Romanian government tolerated their frequent humiliation and exclusion from many professions and government services. Romania engaged in arbitrary expulsions of Jews as vagabonds and tolerated violent pogroms against Jews, many of whom fled to the United States. World War I Due to Romania's unfavorable location between the Russian Empire and Kingdom of Bulgaria as well as King Carol I of Romania's German heritage, Romania had a secret treaty of alliance with Germany and Austria-Hungary since 1883. When the war began in 1914, King Carol I summoned an emergency midnight council where he revealed the secret treaty of alliance. While the king favored Germany, the nation's political elite favored the Entente. As such, the crown council took the decision to remain neutral. When the Austro-Hungarian Empire invoked a casus foederis on Romania and Italy linked to the secret treaty of alliance since 1883, both Italy and Romania refused to honor the treaty on the grounds that it was not a case of casus foederis because the attacks on Austria were not "unprovoked", as stipulated in the treaty of alliance. King Carol I died on 10 October 1914, and his successor, King Ferdinand I of Romania was much more favorable towards the Entente. Promising during his coronation that "I will reign as a good Romanian". In August 1916, Romania received an ultimatum to decide whether to join the Entente "now or never". Under the pressure of the ultimatum, the Romanian government agreed to enter the war on the side of the Entente, although the situation on the battle fronts was not favorable. As a consequence of this "betrayal" toward his German roots, Kaiser Wilhelm II had Ferdinand's name erased from the Hohenzollern House register. For Romania, the highest priority was taking Transylvania from Hungary, with around 2,800,000 Romanians out of around 5,000,000 people. The Allies wanted Romania to join their side in order to cut rail communications between Germany and Turkey, and to cut off Germany's oil supplies. Britain made loans, France sent a military training mission, and Russia promised modern munitions. The Allies