(or the European Championships, or any time their national football team is playing)
Because I really dislike German nationalism, that's why.
It only seems to lead to disaster: disaster for them and disaster for everyone around them. And it does this because it always seems to lead the Germans into a horrible, disastrous combination of arrogance and short-sightedness. They start to think that they can and should pursue some course of action which, while it causes tremendous suffering for other nations around them, seems to be just fine for them – but which in the long run causes disaster for them too, because Europe's countries are small and closely interdependent; none of them exist in isolation. Something that causes most to suffer ultimately always causes all to suffer. Every conflict there is internecine.
They did this in 1914 and they did it again in the 1930s, and the latter episode resulted in such a catastrophe that it kept German nationalism suppressed for decades later. But it inevitably revived as older people died and the collective memory faded, and now it's all happening again.
Joschka Fischer said it so well just over two years ago:
Germany destroyed itself – and the European order – twice during the 20th century, and then convinced the West that it had drawn the right conclusions. Only in this manner – reflected most vividly in its embrace of the European project – did Germany win consent for its reunification. It would be both tragic and ironic if a restored Germany, by peaceful means and with the best of intentions, brought about the ruin of the European order a third time.
The only part of that I even slightly disagree with is the words "and with the best of intentions". To me, Germany's intentions seem nothing but arrogant, foolish and selfish.
At that time Fischer urgently called for Germany to change course, saying that the salvation of the euro and the European Union requires not only "structural reforms aimed at restoring Europe’s competitiveness" but also "political and fiscal unification" and "short-term growth policies". Since then there has been no significant movement by Germany on either of those last two points. Germany has continued to impose its deeply misguided austerity regime on the eurozone with arrogant blindness to its fundamental flaws, its lack of success and the pointless pain it is inflicting in nearly every other country. Analysts are talking more and more about Europe facing a "lost decade" economically.
With the exception of Germany [emphasis added], none of Europe’s biggest economies have returned to the level of economic output they had at the beginning of 2008... The figures suggest that Europe is already well into what could become a lost decade — a period of pernicious stagnation and wasted potential that could have lasting effects on ordinary citizens.
The truth of Fischer's observations two years ago is becoming increasingly clear:
We are once again learning the hard way that this kind of austerity, when applied in the teeth of a major financial crisis, leads only to depression. This insight should have been common knowledge; it was, after all, a major lesson of the austerity policies of President Herbert Hoover in the United States and Chancellor Heinrich Bruning in Weimar Germany in the early 1930s. Unfortunately, however, Germany, of all countries, seems to have forgotten this reality.
Germany's collective memory was once the country's best asset. It seemed to be pretty much the only country in the world that had successfully learned from the past. Now Germany has collective amnesia, and the results are exactly what you would expect them to be.