Invading / starting a war is not the same thing as imperialism.

Invading for territory gain is absolutely synonymous with imperialistic tendencies

The Marxist definition of imperialism is more specific than just “big country invade small country”. In, Imperialism: The Highest Stage of Capitalism Lenin lays out five aspects of what makes Imperialism: the concentration of production and capital has developed to such a high stage that it has created monopolies which play a decisive role in economic life; the merging of bank capital with industrial capital, and the creation, on the basis of this “finance capital”, of a financial oligarchy; the export of capital as distinguished from the export of commodities acquires exceptional importance; the formation of international monopolist capitalist associations which share the world among themselves, and the territorial division of the whole world among the biggest capitalist powers is completed. Imperialism is capitalism at that stage of development at which the dominance of monopolies and finance capital is established; in which the export of capital has acquired pronounced importance; in which the division of the world among the international trusts has begun, in which the division of all territories of the globe among the biggest capitalist powers has been completed. The question of “Is Russia Imperialist” isn’t a moral one, it’s a technical one. So if Russia were do to something that we all agree is morally reprehensible, that’s a separate concern from whether Russia is imperialist. The technicality revolves around whether Russia has developed an oligarchy of Financial Capital, such that its invasion of Ukraine or other flexes of its influence, perpetuates the export of Russian finance capital around the world. As it stands now, I don’t think that’s currently the case, but with Marxism being a dialectal philosophy, I do wonder if this war will accelerate that merging of Bank and industrial capital that Lenin discusses. It’s a Bourgeois states, and there’s financial capital in there somewhere that absolutely has an interest in forming a Russian imperialism. So when people say “Russia isn’t Imperialist”, this is what’s being referred to. You can take it or leave it, but it’s worth getting into the weeds a bit, so we aren’t all talking passed each other

Marxist does not get to exclusively define what imperialism is. A more standard definition is far more reasonable to use. However, your comment is very informative to me, I’m glad you took the time to write this out

“A more standard definition” than the one that’s been in use for over a hundred years?

The Marxist definition is strictly different, not a clarification.

Imperialism is quite literally the highest stage of capitalism. The way liberals use it is just as a synonym for “aggressive”. What definition do you propose that doesn’t make like, the D-Day landings imperialist?

aggression with an expansionist agenda. especially by a country and especially unprovoked. Economically or militarily. D-day wouldn’t be included because the goal wasn’t expansion. Though I would be very surprised if the usa and Europe hadn’t perpetrated many acts that should be included during the full course of the war.