marx was a liberal. that's how he self-identified. he was into rugged individualism as much as any other liberal. and, so was kropotkin.

but, these people didn't think in terms of contrasting individualism with collectivism, or in terms of opposites clashing against each other, at all. these people were hegelians, and they insisted on dialectics as the means of resolving contradictions in thought.

so, to talk of individualism as being in opposition to collectivism is language that would be very weird to any early socialist, including kropotkin. they would have all wanted to speak of a synthesis between individualism and collectivism, and find ways to resolve the contradictions through an application of dialectical thinking - following hegel, but stemming from aristotle.

the idea that you can line these ideas up in contrast with each other is really uniquely american, and comes right out of the cold war. it's vulgar. really.

actual leftists do not talk like this - they don't line up collectivism v individualism or socialism v capitalism or masculine v feminism or anything else like this but rather try to find ways to unite the ideas into holistic concepts that eliminate the conflict within them.

that insistence on dialectical thought is really the foundational point of socialism as a philosophical system - as mentioned, coming directly from hegel.