 In June 1912, along with Constantin Dobrogeanu Gherea, Ecaterina Arbore and others, he represented the Bucharest Socialist Club at the Fifth Congress of the Social Democratic Party of Romania (PSDR), being elected a member in the committee of the party's publishing house.In order to escape harassment from the authorities, Nicolau chose to leave Romania for Paris, where he continued his law studies at the Sorbonne, and joined the French Section of the Workers' International.In 1916, Romania joined World War I on the side of the Entente and imposed an immediate ban on the local socialist movement, which had adopted a militant pacifist stance.