After Bessarabia joined
Greater Romania, a large part of the communist organisation in
Chișinău, the Bessarabian capital, was arrested by the new authorities and put under trial in the
Trial of the 108. Tcacenco received the task of restoring the organisation, and in October 1919 he was elected secretary of the Chișinău communist committee. Later he would be elected secretary of the regional organisation of the party in Bessarabia. Tcacenco was one of the founders of an illegal typography in Chișinău, and was the editor of
Bolșevicul basarabean ("The Bessarabian Bolshevik", in Romanian), and
Bessarabskiy kommunist ("The Bessarabian Communist", in Russian). He also contributed to the restoration of the communist youth organisation in the main city of Bessarabia, and tightened contacts with the local communist-influenced trade unions. At the same time, Tcacenco established contacts with
Alecu Constantinescu, a leading member of
Bucharest's nascent communist movement. The contacts between the two organisations were however soon interrupted as Tcacenco was arrested in Chișinău on 6/7 August 1920, along with several communist activists. Tcacenco succeeded in escaping custody on 17 August 1920, leaving for
Iași. On 19 February 1921, the Chișinău court-martial convicted him
in absentia to death. In Iași, Tcacenco assisted in the organisation of the still chaotic local workers' movement. In March 1921 he participated at the Iași Conference of communist organisations, and was elected in the central committee of the Conference. During the debates, he supported the creation of an unified communist movement, part of the
Socialist Party of Romania, and opposed the creation of several provincial parties, as proposed by other delegates. He and most of the delegates to the Conference were arrested by the Romanian authorities on 26 March and during the following days. Tcacenco was included in the group of communists tried in the
Dealul Spirii Trial (January–June 1922), when the
National-Liberal government attempted to eliminate the Communist Party by making it responsible for a bomb attack on the
Romanian Senate by anarchist
Max Goldstein. During the trial, Tcacenco acknowledged he had participated in distributing communist newspapers and manifestos, but denied any connection with the bomb attack. Most of the defendants were ultimately amnestied under public pressure, however Tcacenco received a 2-year jail sentence. The Supreme Council of Re-examination annulled the sentence on 22 September, and disposed a
retrial to take place at the War Council of the 5th Army Corps, in
Constanța. As the legal proceedings were delayed, Tcacenco escaped custody again on 2 April 1923, and left for Bucharest. He joined the local communist movement, however he was quickly re-apprehended by the authorities. Back in Constanța, the court decided his 1921 activities had a political character, thus falling under the royal
amnesty of 1922. Nevertheless, he was not set free, as he was sent to Chișinău for a retrial of the February 1921 decision. In August 1923 the sentence was quashed, but Tcacenco was ordered to leave the country in 30 days. He subsequently fled Romania, settling temporarily in
Prague,
Czechoslovakia. ==Exile and demise==