During World War I, in 1917, Šinko was mobilized and in 1918 he participated in the establishment of the Hungarian Soviet Republic.

Šinko worked writing for many Hungarian magazines such as: A Tett,[1] Ma,[1] Internationale,[1] Tüz, Korunk, Nyugat, and others.

While in Paris, his articles were published in L'Europe, Le Monde and Ce Soir.

In 1946, he began to devote his energies to literary studies and writings on public affairs.

[4][5] Šinko died on 26 March 1967 in Zagreb and was buried in Mirogoj Cemetery.