The same year
Nikolaos Zachariadis, the General Secretary of KKE was transferred by the
Germans to the
Dachau concentration camp, and Siantos undertook the leadership of the party as acting Secretary General. During the German occupation of Greece from 1941–1944, Siantos led the Communist-dominated Greek National Liberation Army, and he also played an important role in the establishment of the Political Committee of National Liberation in 1944. The same year representatives from all political parties and resistance groups came together at a conference in
Lebanon, seeking an agreement about a government of national unity. According to the September 1944
Caserta Agreement, all the resistance forces in Greece were placed under the command of a British officer, General
Ronald Scobie. Siantos opposed the signing of both agreements, but he then was one of those who argued for their full implementation. After the intervention of the
British forces in Greece led by Scobie in favor of the government, EAM was defeated, and Siantos faced a fierce criticism by his own
comrades for his choices; even Zachariadis called him "agent of the British". In February 1945 Siantos led the delegation of KKE and EAM that negotiated the
Treaty of Varkiza with the Greek government and the other political parties. He signed the Treaty but after only four months he turned the command of the party over to Zachariadis, who returned to Greece. He typically remained member of the politburo, but had no leverage on the party; the defeat of 1944 had cast a slur on his reputation within the party. == Death and legacy ==