If for some inexplicable reason you wanted to reawaken German nationalism, how would you go about it? I suggest a three-part strategy.
First, you would replace the rock-solid German currency by one with very shaky economic foundations, against the wishes of almost the whole German population (which, of course, you would not deign to consult).
Second, you would make sure that same population paid for the gross and dishonest profligacy of the Greek government: a profligacy that was rendered possible by the adoption of the very currency that the German population did not want in the first place.
Third, you would do everything possible to ensure that the crisis will spread, last for a long time, cost a fortune in failed attempts to solve it, and fall mainly to the Germans to pay for.