Ahead of Monday's European Union summit, the only thing you can rule out is a happy ending. Whatever happens at the leaders' meeting -- even if a deal of some sort emerges -- the EU has suffered lasting and perhaps irreparable damage. The available choices run from bad to terrible.
The costs to Greece and to the EU of a default followed by Greece's ejection from the euro system could be huge. But even if the worst doesn't happen, Europe has suffered a total breakdown of trust and goodwill. That can't easily be undone -- and it's a dagger pointed at the heart of the entire project.