 Vesnić became Prime Minister of the Kingdom of Serbs, Croats and Slovenes in 1920, and during his office, he signed the Rapallo Treaty with Italy.During his second government (1920–1921), Vesnić retained the portfolio of Foreign Minister as well.A talented scholar Vesnić wrote dozens of studies regarding international law in general and the position of Bosnia-Herzegovina in the international system after the Austro-Hungarian occupation in 1878, in particular.