Is Stalinism left-wing or right-wing?

The question is ambiguous as all societies & political systems are a mix of agendas. Basically, we need to examine the political agenda, economic agenda and social agenda.

Stalin’s ultimate objective was to convert a mainly agrarian society, to a urban & industrial society, with possibly the long term aim (after numerous generations) of gravitating towards a socialised economy.

Stalin’s major constraint was money supply for foreign exchange to acquire the physical machinery for means of production.

Capitalists (those controlling money supply) in Western Europe & the USA were typically mercenary and exploitative. Another issue that restrained Stalin’s objective was the fact that foreign governments in the West, had the counter objective of “Economic Imperialism” (Economic Colonisation) through the provision of enduring debt. Thus Stalin’s nationalism comes into play, and all nationalistic objectives are considered of the extreme right in politics & society.

Whereas Trump has the slogan “Lets make the USA great again”, Stalin had the objective of “Lets make Russia equivalent to all the great world powers”. The bit Trump & Stalin left out is to meet their objectives required the economic exploitation of the masses. Same extremist right-wing, anti-Christian (see Acts 4:32–35) rhetoric.

Imo, like Fascism, politically Stalinism is an extremist right wing movement advocating central control (dictatorship), something like the USA under Trump seems to want to emulate.