The reason we have a 'strange obsession' with WW2 is that we had a unique experience in it - bombed, starved, battered, but never conquered, and ultimately (on the back of USA/USSR) victorious - which conditioned that entire generation (and, more potently, their kids) to believe in a form of exceptionalism.

In fact, the obsession is not strange in the slightest.

The rest of western Europe were either Nazis, or were conquered/occupied by Nazis, which is a different national experience altogether and I imagine provoked a lot more humility and also shame.