Comnen received international attention, as well as collaborations from Emil Isac, Constantin Flondor, and Ghiță Popp.Petrescu, pp. 333–334 He also approached the Czechoslovak National Council and established a working relationship with Edvard Beneš. Eventually settling with his family in Bern, he was delegated to Geneva by Prime Minister Ion I. C. Brătianu, and was later one of Romania's envoys to the Paris Peace Conference. While in Paris, he published the bilingual atlas Roumania through the Ages. . It was at this time that Comnen became the target of criticism from the far left—communist writer Panait Istrati, who also resided in Switzerland, alleged that Brătianu's delegates Vasile Lucaciu and Petrescu-Comnen were demagogues, preparing the annexation of Transylvania to the "satrap yoke" of the Romanian Kingdom. Mircea Iorgulescu, "Istrati în Elveția (II)", in Revista 22, Nr. 708, September–October 2003 Petrescu-Comnen's input was valued by the Transylvanian delegate, Alexandru Vaida-Voevod, who kept him as an adviser during meetings with Robert Lansing. By then, Comnen had befriended Lansing's nephew, Allen Dulles.
