If Greece leaves, many pro Euro spinners will claim they were a victim of the markets. The markets are only doing what they are doing because of the way people in the Euro area are acting.
Every Greek or Spaniard who transfers their money out of a Euro bank account in their country to a safe haven or into a foreign currency is helping undermine the Euro. If no-one did that, there would be no market worry about a run on the banks, no reduction in bank deposits.
Every Greek who decides to trade in cash to evade Greek taxes is helping undermine Greek state finances. Every Greek public sector worker who understandably resists cuts in spending makes it more difficult for the Greek state to live within its means. If Greeks generally paid more tax and demanded less public service there would no state debt and deficit problem.
Every German who says this is not our problem, who says they have no wish to pay any more, is behaving understandably but is thwarting the security and understanding of the weaker economies. They were expecting German support and rescue.
Many of the people will claim they were a victim of the politicians. That is always a popular explanation. In one important sense they are. It was the political class who drove them into the Euro, and the political class who told them it would work just fine. In another sense they are victims of their neighbours. If you vote for the vision of the Euro, you have to live with its many problems and imperfections, and do your bit to help offset them. That means paying the high taxes the scheme needs, accepting financial obligations to all parts of the zone and keeping your money in your home banks whatever the rumours.