Contrary to the assessment of some Bulgarian historians the Romanian position was not weakened by Germany but rather by the Soviet Union. After having occupied Bessarabia in June 1940, the USSR considered Bulgaria a more friendly country than Romania and considered that it would be in its interest to have a common border with Bulgaria. Therefore, the soviet diplomacy was encouraging the Bulgarians not to be satisfied with the Cadrilater, but to demand the transfer of its sovereignty over the entire Dobruja. Besides creating a common border between the Soviet Union and Bulgaria, this also presented the potential advantage for the Soviet Union of gaining control over the Danube Delta. As the Delta was not part of the Dobruja, it would not have been occupied by Bulgaria, but the possibility of Romania maintaining sovereignty over a territory to which it could have access only through a reach of the Danube bordered by unfriendly nations, was doubtful. During an audience, king Boris III of Bulgaria informed Eugen Filotti about the soviet intentions. This induced the Romanians to accelerate the negotiations and to reach an agreement before the Soviet Union would intervene in a more aggressive way.