on 1 december, the division became the 27th mechanized division. it was reduced to regimental strength a year later. in 1946, he served as a witness at the tokyo war crimes tribunal. grebennik continued to command the division throughout these changes but returned to the border troops in august 1947. he was appointed deputy head of the border troops in the transcarpathian border district. grebennik was appointed head of the border troops of the ukrainian border district in december. while in that position, he participated in the fighting against the ukrainian insurgent army. between 1950 and 1954, he was a deputy of the supreme soviet. in november 1951, grebennik was appointed head of the border troops of the leningrad district. he became a senior advisor to the albanian ministry of interior affairs in october 1953. grebennik became the head of the 1st department of the main directorate of border and internal troops of the ussr in october 1956. during the crushing of the hungarian revolution of 1956 in operation whirlwind, grebennik commanded the soviet forces in the budapest region and was wounded. from april 1957, he was the chief of staff and first deputy chief of the kgb border troops. in july, he was promoted to lieutenant general and became the head of the kgb border troops in the southwestern frontier district. from january 1960, grebennik was the head of the operational group of the kgb border troops in the ukrainian soviet socialist republic.