Marx and Engels judged other national movements by German national interests

Evidence

As analysts of nationalism, their legacy then was ambiguous. It appears that with respect to the actual nationalist movements of their time, in Germany, Poland, eastern, or southern Europe, neither Marx nor Engels achieved an extraordinary comprehension or fully escaped the parochialisms of the day. Rather, their historical method provided them with a means of supporting their predispositions on the historical worth of peoples and the varying capacities of the several European national movements. Their own nationalism whether “unconscious or subconscious,” as Davis is forced to concede, or otherwise, made them generally unsympathetic to the national liberation movements of peoples (e.g., the Russians and other Slavs) that historically threatened what Marx and Engels believed to be the national interests of the German people. An opposition to movements such as these could be rationalized by their failure to accord with the practical requirements of a viable political economy. — Cedric J. Robinson, Black Marxism_ The Making of the Black…, 358