From the March 1980 issue of the Socialist Standard
Nationalism and socialism are incompatible for a number of reasons. First, the basis of all nationalist theories is that those supposed to make up a “nation” have a common interest. This is not true. All “nations”, however defined, are divided into two antagonistic classes: those who own and control the means of production and distribution and those who don’t and are thus dependent on selling their mental and physical energies in order to live. Between these two classes there is an irreconcilable conflict of interest which can only be resolved by the conversion of the means of production into the common property of the whole community, by the dispossession of the owning class.
In preaching a community of interest between all the members of a supposed “nation”, owners and non-owners, nationalism obscures and diverts attention from this class struggle, thus making that struggle less effective and postponing its final solution through the establishment of socialism.
Nationalism also assumes that the problems facing the non-owning class can be solved on a national scale, within the borders of a particular state. This is quite wrong. Capitalism is the cause of these problems. And since capitalism is a system existing all over the world (in state capitalist Russia and China as well as in the West) it can only be abolished on a world scale. Because capitalism is already a world system so must be the new, higher form of social development which will replace it. The idea of “socialism in one country” is absurd and any attempt at it is bound to fail, leading probably to some kind of state capitalism.
This socialist opposition to nationalism applies equally to nationalist movements such as those in Ireland and Palestine, which are generally regarded in leftist circles as "progressive”. Since about the turn of the century, when capitalism became the dominant world system, only one movement can legitimately be called "progressive”, namely, the movement for world socialism.
Before that time, in the 19th century, a case could be made for certain nationalist movements being historically progressive and hence worthy of the support of socialists. This was the attitude taken up by Marx and Engels towards the movements for German and Italian unity and for Polish and Irish independence. At a time when capitalism was not yet the dominant world system, they felt that it was their duty to help the development of capitalism and to weaken its enemies (in particular Tsarist Russia).
In the changed conditions of the 20th century, with capitalism as the dominant world system, the reasons given by Marx and Engels for supporting certain nationalist movements are no longer valid. Capitalism no longer needs to be helped. This is why we say that Marx and Engels’ views on nationalism are now out-dated and obsolete and that those who repeat them in the changed conditions of today have not understood the first thing about Marx’s method.
The European Social Democratic movement of before the first world war made two fatal mistakes. One was to advocate reforms to be realised inside capitalism. The other was to refuse to be anti-patriotic. On the contrary, to declare themselves to be patriotic Frenchmen or Englishmen or Germans. It was thus inevitable—and logical from their own, mistaken, point of view—that they should have lined up behind their respective governments when the first world war broke out in 1914.