In August 1916, Romania entered the war and invaded Transylvania, but an attack by the Central Powers from the south ruined its actions. The Romanian army was courageous and enthusiastic, but it was poorly equipped and inexperienced. In December, the Central Powers had already occupied Wallachia and Dobruja. This raised doubts for the Entente as to whether Romanian claims had to be accomplished, and they did not invite Romania to participate in following conferences about the war. This changed after a visit to Moscow from Brătianu complaining about this and in which he convinced the Entente of the importance of Romania in the region. Eventually, the Russian army collapsed and Russia would be forced to abandon the war. Romania, although it had managed to repudiate an offensive towards Moldavia, was left alone on the Eastern Front and was now worried about the threat of the Russian revolutionary forces. Thus, it signed the Armistice of Focșani with the Central Powers on 9 December 1917. Meanwhile, Bessarabia, which had declared itself as the Moldavian Democratic Republic in 15 December, united with Romania on 9 April 1918. This was ratified by King Ferdinand I on 17 April.