Hartwig was a key figure in the formation of the system of alliances formed in 1912 between Serbia and Bulgaria, Greece, and Montenegro (the Balkan League). He was a violent opponent of Austria and, along with Sazonov, thought of the alliance system as being primarily oriented against Austria. As a Pan-Slavist, however, he was not opposed to territorial gains at the expense of Turkey after the conclusion of the Balkan Wars, and was one of the first to reject the territorial status quo line then pursued both by Sazonov and Count Berchtold, the new Austrian foreign minister.