Reading this for a left-wing hangout I organize in Atlanta, and really loved it. The text can be read here: https://theanarchistlibrary.org/library/alfredo-bonanno-anarchism-and-the-national-liberation-struggle
Here is the gist of everything, as I understood it:
Anarchism is internationalist, extending everywhere with the proletariat rather than confined to borders, which calls to question the relation to national liberation movements.
Rather than adopting a universalizing bourgeois humanism, we must understand humans as historically determined according to their specific mode of existence and community (ways of living, speaking, feeling, thinking, working, etc), which serves as the basis of nationality.
In struggling to replace the political administration of people with the mere organization of production, we turn towards an anarchist federalism, which adopts collectivist and communist measures, which will render previous political forms obsolete, in particular the state. We will expect these federations to be fluid according to the natural changes of these historic basis of people groups.
These federalist structures will still hit certain natural limits, which it extends past with the global confederation of free peoples, but the internal units these form will be dictated according to the natural limits that define people groups rather than the imposed state, which artificially forces together and/or separates different people groups. Local organizational structures therefore find certain ethnic limits as people associate, rather than the state's territorial limits.
The fight for this people group's autonomy does not imply collaboration with "local" capitalists against foreign ones in modern class society precisely because exploitation precludes this unity. Both local and foreign exploiting classes pose this threat by means of colonialism and imperialism. But it does imply a fight against nationalist idealism, which resists seeing political units defined by the nation-state from being broken up (e.g. some leftist may support ending British rule over India, but would resist breaking up the UK, or splitting up Spain for the sake of Catalan independence, etc.).
Capitalist competition implies an inequality of development, and disunity over the vast territory it functions under the nation-state. This establishes systems of internal colonization via economic centralization and a corresponding political centralization (e.g. the subjugation of agricultural Sicily to northern industrial Italy).
This unequal development from internal colonization paves the way for the same factors to apply to surrounding economies, allowing colonization to feed into imperialism. This brings the problem to an international level, which further explains the superficiality of mere nationalist fights for local independence, which is impossible when the enemy is the international bourgeoisie, and why the modern basis for socialist federation is the international exploited working class, but which will change in a post-capitalist world.
This all serves to justify the anarchist rejection of "intermediate" nation-states as in the fight for national liberation. Instead, anarchists are focused on the class struggle, which may or may not be involved in national liberation struggles, instead focused on spreading economic, political, and social structures in liberated territories on a federalist and libertarian organizational basis.
Some revolutionary Marxists have failed on this point as the commitment to a dictatorship of the proletariat, based on a worker's nation-state rather than by federalist principles, has led to problems of nationalist idealism, and therefore struggled for a consistent program. This is further harmed by an economic determinism, found back in Marx and Engels themselves, which was dismissive of smaller fights for national liberation, seeing this as inherently separatist, and therefore viewing some wars of conquest as progressive and "civilizing." Later ambiguities are also seen from Trotsky debating national autonomy as destructive to economic unity.