Late in 1927 Dozenberg was recruited into the underground Soviet military intelligence network, for which he worked for more than a decade under the pseudonym "Nicholas Ludwig Dallant."
[1] Dozenberg emigrated to the United States in 1904, settling in the Boston suburb of Roxbury, Massachusetts, center of a large Latvian community.
[8] In 1921, Dozenberg moved to Chicago to become business manager of The Voice of Labor, a legal weekly publication of the underground CPA edited by Jack Carney.
[1] Upon the termination of The Voice of Labor, Dozenberg became the "Literature Director" of the Workers Party of America, the legal embodiment of the then-underground CPA.
[10] Dozenberg was active in Workers Party affairs and was a delegate from the Chicago district to the organization's December 1922 convention in New York City.
Dozenberg was listed on the masthead of The Worker, the party's surviving weekly as its business manager in 1924, but in 1940 Congressional testimony he had no recollection of having held this position.
[12] He was similarly listed as business manager of The Liberator, the Workers Party's literary and artistic-related monthly magazine from New York, in the same period but likewise retained no recollection of having held that post.
[10] Dozenberg stopped paying dues and dropped out of the Communist Party at this time so as to lower his profile with the American secret service.
[18] Dozenberg dropped out of the Communist Party on instructions and began meeting frequently with Tilton, obtaining a first passport under the pseudonym of "Nicholas Dallant" in March 1928 and a second one underhis own name in November of that same year.
[19] Dozenberg testified to Congress that in the early 1930s he was dispatched on a mission to Bucharest, Romania, to establish a motion picture company which was to be a front for Soviet military intelligence.
[20] Not only would the firm provide a plausible business cover for agents coming and going, but a company purportedly making movies would have a relatively easy time surreptitiously filming ports and military fortifications, it was believed.
[2] In 1931, after traveling between Germany, the Soviet Union, and Romania in the previous year, Dozenberg returned to the United States and established the American Rumanian Film Corporation in New York.
[2] Towards the end of 1933, Dozenberg was dispatched to China on a new mission establishing yet another business cover for GRU operations, this time with a view to gaining information about Japan.
While in jail, he was called before the House Committee on Un-American Activities (HUAC) to give testimony on secret Soviet intelligence operations in America.