Worries about the Greek debt deal were offset last week by greater optimism towards Germany. Not only were there further signs of a pick-up in the economy, but Angela Merkel hinted that she would be prepared to sanction a bigger bail-out fund. But even if the German economy strengthens further, that may not help the rest of the euro-zone. Equally, there are few signs that Germany is about to allow a let-up in the deflationary austerity gradually strangling the weaker euro-zone economies. If Germany is going to save the euro, much bigger changes will be needed.