Pillai was among those who first gave the slogan of "Jai Hind" to the people of India and to the many Indians abroad who were struggling for the cause of Indian Independence. He had the privilege of being the Prime Minister of the Provisional Government of India set up in Afghanistan in December 1915, with Raja Mahendra Pratap of Kabul as President. However, the defeat of the Germans in the war shattered the hopes of the revolutionaries.
The Germans were all along helping the Indian revolutionaries with a selfish motive. Though the Indian patriots made it clear to the Germans that they were equal partners in their fight against the common enemy – British imperialism – and what was expected of them was help by way of funds, arms, and ammunition, to the revolutionaries who were abroad and at home fighting the British, the Germans wanted to exploit the revolutionaries for their propaganda work and gathering military intelligence. When they started losing the battle, the Germans lost their interest in the revolutionaries and even started looking upon many with suspicion. This strained the relationship between the Indian revolutionaries and the Germans. Pillai raised his voice against the view of Adolf Hitler that Indians were still incapable of ruling themselves, and he even forced Hitler to apologise in writing. But he fell a victim to the wrath of the Nazis. In 1931 Pillai had married Lakshmibai of Manipur, whom he had met in Berlin. The Nazis killed Champakaraman by poison on May 26,