Godwin's law states that in any internet conversation, no matter the subject, someone will eventually mention the Nazis. It's called the Reductio ad Hitlerum, and it tends to be the sign that the debate has descended into trollish insignificance, sound and fury.
I think that's why my knee-jerk reaction to Angela Merkel's speech to the German Parliament on Wednesday was disgust. Why, I wondered, were the important people stooping to this hackneyed tactic, when millions of bloggers know it's social media suicide?
But then I thought about what she said, and the position she was saying it from.
'No one should think that a further half century of peace and prosperity is assured. It isn't. And that's why I say that if the euro fails, Europe will fail - and that mustn't happen.'
Merkel is unique among the engineers of the current euro deal in having first-hand experience of what happens when Europe fails, from her childhood in East Germany. Her political career grew out of reunification, when the deep scars left on the country after World War II could finally be bandaged, if not healed.
Perhaps that's why it was Merkel who sat Europe's bankers down in a private room and told them how badly they needed this not to fail. It took someone with the authority of personal memory to remind us how recently, and how terribly, peace fell apart in Europe. It took someone with a deep awareness of how much is at stake to intimidate, manipulate and persuade the politicians, bankers, and people of Europe into agreement.
For me, a child of '89 in Britain, that awareness is almost purely theoretical. Evoking the spectre of past wars struck me, initially, as a rather sensationalist attempt to pressurise the Bundestag and get this done, whatever it takes. She gave them a choice, but made it very difficult to turn her down.
I suppose that's the point, really. Merkel has shown a rock-hard determination, in the face of huge home opposition, and at great risk to her own political career. She has been the political manipulator the Eurozone needed. However shaky the long-term forecast, she has succeeded, for now.
'The world is looking at Germany,' she said on Wednesday, wondering 'whether we are strong enough to accept responsibility for the biggest crisis since the Second World War'
There's a poetic justice in Germany's unquestionable leadership in this new crisis. Germany's Chancellor knows, with absolute certainty, that Europe must not fail. And her country may be the only one strong enough to save it.