Because breaking the Euro requires, in extremis, only one member government (but realistically more like a handful) deciding to bugger this for a game of soldiers.

Breaking austerity without breaking the Euro requires a supermajority of member governments to take a sufficiently strong stance against austerity. And that supermajority must include Germany.

And I cannot tell a plausible story about how to build an anti-austerity coalition big enough and powerful enough to bully Germany into unconditional surrender on the most important German foreign policy objective of the last forty years, without passing through a several months (or years) long stage where the anti-austerity coalition is:

• Big enough and strong enough to break the Euro.
  
• Big enough and strong enough to pursue anti-austerity policies outside the Euro.
  
• Not big enough and strong enough to dictate policy to Germany.
  
• Under extreme pressure from their own stakeholders to deliver on their anti-austerity promises in order to retain sufficient legitimacy to be able to effectively govern.

If the process of building an anti-austerity coalition will break the Euro anyway, then there is no reason not to gather up anti-Euro dissidents with other motives than ending Austerity - anti-Austerity dissidents who do not have the stomach to, if necessary, break up the Euro will break off anyway once push starts coming to shove.

- Jake

Friends come and go. Enemies accumulate.