Socialist understand that in a democracy socialism has to be imposed equally. Ultimately that will require an international solution. For example while the UK managed to export 1 million of it citizens to the EU it imported 3 million EU citizens. This left an extra 2 million sucking off of the UK social system resulting in increasing costs and decreasing services!
This would be one of the main causes that lead to BREXIT. Certainly there were others. But the International Socialist movement and their media allies have been working very hard over the last few years to reverse this result!
But I would argue that while the USA continues its decline that the EU will need to take a more nationalistic approach in order to defend itself from the country that started this “socialist” trend! That of course flies into the face of internationalist principles and we will see if the EU can adapt to changing political circumstances much in the same way that Lenin did with his Marxist principles.