The European left must adopt the cultural nationalism of the far right, before it's too late.
Please elaborate.
People care about two things (1) economic populism, and (2) identity politics. The left's advantage historically was (1), while the right's advantage was (2). However, the European right has caved on (1) and embraced the leftist position. Therefore, unless the European left caves on (2) and embraces the rightist position, all is lost for the left.
I largely share your analysis but rather than (1) being won by the Left(?!), it's been forfeit, whilst (2) is alive and well in politics, and allows the Right dominance. My solution would be then for the Left to re-adopt (1) (and to hell with how capital reacts).