If we're time travelling for theories of imperailism, why stop at Lenin? What about Marx & Engels' opposition to some nationalist movements in Europe?
e.g.
"For Marx, the modern working class was the agency for the overthrow of class society, 'human emancipation', made possible by capitalism because of the development of the productive forces. Politics, therefore is concerned with the growth and consciousness of the working class. What serves that end is progressive, what hinders it is reactionary.
The judgement obviously depends on circumstances, and therefore cannot be reduced to a set of slogans. The attitude of Marx and Engels to the national question is an excellent illustration of their method.
In 1848-49, as participants in the German revolution, they strongly supported the establishment of a united German bourgeois-democratic republic which would, they believed, facilitate industrialisation and the rapid growth of a class-conscious working class. German unity, on this basis, idvolved the destruction of the Austrian Empire (as well as the Prussian Kingdom and a large number of petty states).
The Austrian Empire, occupying a huge block of central Europe, contained Germans, Hungarians, Czechs, Croats, Poles, Slovenes, Italians, Rornanians, Ukrainians and Slovaks.
Marx (and Engels) supported Italian, Polish and, above all, Hungarian national movements against Vienna. They opposed Slav nationalism (except Polish nationalism). So they were simultaneously supporting and opposing the right of national self-determination. For those who think in terms of abstract formal principles this seems a scandalous position and Marx has often been accused of German chauvinism and anti-Slav prejudice.
In fact Marx's position was entirely consistent from a working class point of view. Self-determination is a pot that can contain many different brews. In the actual circumstances the emergence of an independent Hungary in 1848 was the biggest obstacle to the re-establishment of Hapsburg power after the dynasty had managed to regain power in Vienna. Therefore it was progressive.
It is as well to look at the argument critically. Hungary was not supported on social grounds, still less on sentimental ones. The national movement was not even bourgeois. It was the nobility that constituted the national movement, admittedly an exceptionally large nobility (8-10 percent of the population). Moreover "the lands of the crown of St Steven" - the territories claimed by the revolutionaries - were not even all ethnically Hungarian; less than half their population spoke Magyar.
The criterion was simply that the Austrian Emperor and the King of Prussia were twin pillars of reaction and behind them stood the Tsar - "the gendarme of Europe". Movements which weakened these were to be supported.
Now Slav nationalism - Croat nationalism most importantly - was directed against Budapest, not Vienna. It was, objectively, a tool of Hapsburg reaction. Croat soldiers fought the Hungarian revolution at a time when the Emperor could not rely on German Austrian troops.
To summarise, the fate of the European (French, German) revolutions was the decisive consideration.
The fact that reaction - in desperate crisis - could use the language of rebellion and even appeal to genuine national (or quasi-national) feelings was not decisive. Nor were considerations of whether this or that group had, or had not, some formal 'national' characteristics. Marx would have had no difficulty in dismissing the 'national' claims of the Orange Order in Ireland.
On this point, it should be noted that Marx's unwavering support for Irish nationalism was not at all due to sentimental consideration. It was because this nationalism was directed against the English ruling class and because that class used the Irish issue to divide its own workers and subordinate them to reactionary national prejudices. His famous statement "No nation which oppresses another can itself be free" was made with Ireland and the British workers in mind."
Duncan Hallas, 1986, Marx and politics, Socialist Review, No.83, January 1986, pp.17-9. http://www.marxists.org/archive/hallas/works/1986/01/politics.htm