In 1925, he moved permanently to the USSR, where he worked as a translator, researcher and professor, authoring numerous articles on South Asian society and revolutionary strategy.

[2] Speaking at a 1919 London conference demanding the withdrawal of British troops from Russia, he was billed as a member of the Industrial Workers of the World.

[7] The anti-socialist British Empire Union wrote a letter to the Home Office dated 15 January 1919, warning them about this event due to its organizers' links with Vladimir Lenin, Leon Trotsky, and Rosa Luxemburg, the presence of activists like Sylvia Pankhurst, and an alleged connection between Lohani and "the Chicago trials".

[12] In May 1921, following discussions between the Soviet government and remnants of the Berlin-based Indian Independence Committee,[13] Lohani visited Moscow alongside fellow independence fighters Chatto, Pandurang Sadashiv Khankhoje, Bhupendranath Datta, Nalini Gupta, Abdul Hasan, and Agnes Smedley, to take part in the Third Comintern Congress as representatives of India.

Alongside Chatto and Khankhoje, Lohani challenged the "left" communist line of the existing Communist Party of India (founded in Tashkent in 1920 by M. N. Roy, Abani Mukherji, and M. P. T. Acharya) by publishing a 14-page document, "Thesis on India and the World Revolution", which they sent to Lenin and the ECCI on 7 July 1921, and presented to the Oriental Commission of the Third Congress.

[19] The second part called for an anti-imperialist united front with nationalist groups,[20] arguing that national liberation was a necessary first step toward proletarian class consciousness.

[21] The final part of the document targeted British imperialism, "more than any other bourgeois coalition in existence today" as the main "menace" to Soviet Russia and world communism.

[23] They pointed to the weakness of the Communist Party of Great Britain, which they explained by the presence of a large "Labour Aristocracy" within the British working class, complicit in the imperialist system and unwilling to oppose colonial exploitation.

[24] The thesis had indirectly undermined the existing authority of Roy and the "Tashkent" CPI by calling for a new propaganda organization to recruit advanced workers in British India.

[25] Speaking in defense of the thesis, Lohani went further and called the CPI a "bogus party", demanding it be disaffiliated from the Comintern and a new organization formed to replace it.

[26] Ironically, Muzaffar Ahmad later cited Lohani's indirect admission of the CPI's Comintern affiliation as proof of the party's legitimacy.

[2] The memorandum insisted that the CPI had been founded prematurely by Europe-based expatriates and dubious communists,[25] and reiterated the demand for a propaganda organization on the ground as the prelude to forming a real party.

Roy claimed that Lenin received them in person (minus Lohani who was not considered senior enough), but the Soviet leader refused to commit to anything, and greatly disappointed them.

[35] According to Chatto, the main reason was that Comintern leaders Karl Radek and Bela Kun supported Roy, and prevented the Berlin group from meeting Lenin and Grigory Zinoviev.

[39] Roy had a poor opinion of Chatto and Smedley, but stated Lohani was an excellent orator who acted as the Berlin group's main spokesperson and author.

[40] From 1921–1925, Lohani moved frequently between France, Germany, and Switzerland, supporting himself as a journalist, translator and language instructor, and remaining politically active.

[2] In 1922 he published an article praising Mahatma Gandhi's organizing abilities, and acknowledging some merits of his civil disobedience tactic for the independence struggle.

[2] Living in Moscow as a Comintern operative, Lohani wrote a number of articles on South Asian society and revolutionary strategy.

[44][43] In his writings for the Comintern, Lohani repeatedly stated that a revolutionary crisis in British India was approaching, that dominion status and reform efforts were inadequate bourgeois measures, and only the worker and peasant masses could lead the revolution.

He worked as a translator for radio broadcasts and written publications,[1] and acted as the interpreter for Motilal and Jawaharlal Nehru when they visited the USSR in 1926.

[52] The Comintern was moving toward the Third Period, a leftist policy of abandoning united fronts (such as the CPI's alliance with the Workers and Peasants Party) in favor of immediate preparations for independent revolution.

[53][54] Pyotr Abramovich Shubin (representing the USSR) criticized Roy as the true inventor of "decolonization" theory, claiming that Lohani had merely given it a name.

[57][55] Defending himself again two weeks later, Lohani reiterated that he believed the class struggle in British India was intensifying, the bourgeoisie was counter-revolutionary, and the masses were leading the way.

At the 10th Enlarged Plenum of the ECCI in July 1929, Lohani finally renounced his old views and declared himself in agreement with the new Comintern line.

[67] In the 1930 article "Browder vs. Luhani", The Militant, newspaper of the Trotskyist Socialist Workers Party (United States), mocked Earl Browder's Third Period denunciation of the "bourgeois slogan of 'Constituent Assembly'" by noting that "Luhani, the Stalinist who replaced Roy" had called for a Constituent Assembly for British India in 1928.