In 1913 he was accused of involvement in the assassination of Mahmud Şevket Pasha and sentenced to fifteen years of exile in Sinop.

In July 1918, he helped organise the Congress of the Turkish Left Socialists, held in Moscow, and in November, he became involved in Muskom.

[1] In 1918 he founded Yeni Dünya (New World) in Moscow and used it to popularise the foundations of scientific socialism to Turkish prisoners-of-war.

He was possibly murdered by a group of supporters of Enver Pasha from Trabzon, apparently because of the fear that Suphi might expose Enver Pasha's plans of political activities in Moscow and his ultimate intention of using the Bolsheviks to regain power in Turkey once the Turkish National Movement were defeated.

[5] Suphi was killed by Sailor Yahya together with his communist comrades while traveling to Batumi in the Black Sea on 28 January 1921.