On September 1, 1918, returning to Paris, Stroescu joined Vasile Lucaciu and Ioan Cantacuzino in creating a National Romanian Action Committee for promoting the cause of Greater Romania in Allied countries. He later attached himself to Take Ionescu's National Committee for Romanian Unity. Following the November Armistice, Marghiloman was deposed and Romania, Bessarabia included, reentered the war. In December, this step ensured the Transylvanian union, with the new borders awaiting international recognition at the Paris Peace Conference. Throughout the following months, to Marghiloman's worry, Western powers seemed to favor placing Bessarabia, in whole or in part, under a League of Nations mandate. In March 1919 (some two months into the conference), Stroescu also came out in support of other pan-Romanian causes. He became honorary president of the League for the Liberation of Romanians in Timoc and Macedonia; its executive leaders included George Murnu, Sever Bocu and Tache Papahagi.