Between 1953 and 1956, the North Vietnamese government instituted various agrarian reforms, including "rent reduction" and "land reform", which resulted in significant political oppression.[108] During the land reform, testimony from North Vietnamese witnesses suggested a ratio of one execution for every 160 village residents, which extrapolated nationwide would indicate nearly 100,000 executions.[109] Because the campaign was concentrated mainly in the Red River Delta area, a lower estimate of 50,000 executions became widely accepted by scholars at the time.[109][110] However, declassified documents from the Vietnamese and Hungarian archives indicate that the number of executions was much lower than reported at the time, although likely greater than 13,500.[111] In the South, Diệm countered North Vietnamese subversion (including the assassination of over 450 South Vietnamese officials in 1956) by detaining tens of thousands of suspected communists in "political re-education centres".[112][113] This was a ruthless program that incarcerated many non-communists, although it was also successful at curtailing communist activity in the country, if only for a time.[114] The North Vietnamese government claimed that 2,148 individuals were killed in the process by November 1957.[115] The pro-Hanoi Việt Cộng began a guerrilla campaign in the late 1950s to overthrow Diệm's government.[116] From 1960, the Soviet Union and North Vietnam signed treaties providing for further Soviet military support.[117][118][119]
