By cutting them off from the support of the public (or rather that part of the elites. They are ot monolithic). That means, stick to a narrative of creating peace and prosperity. Reminding the public of the debt conference 1953: it is not necessary to love the Greeks in order to forgive their debt, as it wasn't necessary then, when it was German debt. All it needs is acknowledging the fact that all of us live better by writing off this debt. With the nationalistic narratives we all can only lose.