Aren't Nationalism and Socialism contradictory? I mean in one the people serve the State while in the other the State serves the people. Not as dumb as Anarcho Capitalism, but still silly.
Yes. Fools will tell you the Nazis were socialists, people of a normal intelligence will tell you that calling yourself a duck does not make you a duck.
The issue is that both terms are valid and well defined in political science, but "socialism" and "national socialism" are not significantly related and it is disingenuous to even call national socialism a type of socialism.
There's a tension between socialism and internationalism. If you're going to tax the wealthy to give money to the poor, you run the risk of the wealthy leaving the country and more poor people arriving. There's also the issue of many voters not being super solidaric with those who are not like them. In a sense, all socialism ends up being national by necessity. I don't think that's the worst thing ever. The policy combination of welfare and tight borders (or at least a citizenship that's hard to get) does not inevitably lead to concentration camps.
There's no tension. They can leave but they can't take everything with them. And even what they can take they can only do it for so long before they run out of places to run to.
One big reason you need self-sufficency within individual socialist districts. Taxation is just a tool to rebalance the scales. But at the end of the day, socialists need sovereignty - control over their natural resources and freedom from outside economic extortion.
That doesn't preclude internationalism. But it does preclude imperialism.
Other way around. All socialism must be globalist or you're simply exporting the exploitation. The fleeing of the oligarchy is irrelevant to actual socialism, as their stolen wealth should have been seized, and is only a problem for liberal welfare state models like social democracy.