Stalin was less tolerant of national minorities than Lenin.
As he was from a Georgian background, it is likely that Stalin felt the need to constantly prove himself.
Stalin's instinct was always greater centralised control.
Under Stalin, significant internal deportations were carried out in order to prevent large groups of national minorities being able to organise themselves in a particular area to oppose the regime.
Large numbers of Finns and Poles were deported from eastern areas of Belarus and Ukraine.
In 1937, Koreans were deported from the east of the USSR and Kurds from the Caucasus.
As war approached, more Poles, Germans and Romanians were deported from the western edges of the USSR.
It can be argued that the famine of 1932-34 was partially created by Stalin's determination to crush any separatism in areas such as Ukraine.
Due to starvation, Ukrainian nationalism was unlikely to pose a threat to Stalin during the 1930s.
Stalin even refused foreign aid to help Ukraine.
Due to the famine, many Ukrainians did little to help resist the Nazi invasion of the USSR in 1941.
As the prospect of war increased, Soviet propaganda was increasingly focused on a nationalistic Russian message.
Stalin was depicted as a potential war leader, following in the footsteps of other great Russian leaders.
Expressions of non-Russian identity were less tolerated.
In the Great Terror, there were many victims from the national minority areas who were deemed not loyal enough.
Learning Russian became compulsory in 1938 in all schools across the USSR.
Anti-Semitism also rose in the 1930s.
The collectivisation drive and campaign against the kulaks was often accompanies by anti-Semitic rhetoric in areas with a significantly rural Jewish population.
When the USSR invaded and took over eastern Poland in 1939, 2 million more Jews came under Soviet control.
Many rabbis and Jewish religious leaders were arrested in the aftermath of the 1939 Polish invasion.