> That requires buying into the very concept that "colonialism" is a specific sin different (and worse) from ye olde "I am stronger than you and will occupy your territory and take your wealth".

It does, yes, and completely reasonably so. That's why it has a different name.

> .. as if somebody decided that theft of, say, a smartphone, was a separate and much graver offence...

Yes, it is like that indeed and I'm sure you'll recognise the difference between intellectual property theft and the theft of a car, or the difference between stealing food from a supermarket and stealing food from a beggar.

> I don't really buy it

> It only makes sense to me if there is an underlying ideology

Ok? Maybe read some more about it. Right now it feels like you're the one pushing an ideology without really making an argument for it.

> It may also come handy for distraction from domestic governance failures

Yes, it might. Governments have a host of ways to distract the public from issues. That doesn't change the reality of the history of, or contemporary effects of, colonialism.

> ... similar to the way the contemporary Russian propaganda ...

Boogeyman argument and an emotional appeal.

I have read quite a lot about it and my conclusion is what I wrote above. A mostly ideological distinction without real difference - even less difference than your examples of theft (intellectual property aside - that is not theft by any definition, but infringement).

People have always tried to conquer other territories, make use of them and settle them. To make an artificial slice out of this continuous and omnipresent phenomenon and call it by another name is incoherent, but then ideologies are mostly incoherent, and colonialism as a very specific sin was a very good and efficient argument in Cold War propaganda and its struggle for influence in the Third World.

Soviets excelled in propaganda, and many of their ideas (like AIDS being an artificial disease, unilateral nuclear disarmament, or the fake contrast between colonialism and membership in the Socialist Bloc) survived the fall of the country.

That said, a very similar line was already pushed by the Japanese in order to paint their own brutal empire as some kind of Pan-Asian utopia. But their trace in global discourse is negligible to the Soviet one, which was much more sophisticated and long-lasting.