Euro-Brady Bonds

There is one aspect I don't get about the €110 billion Greek bailout (which is big enough to save Greece the bother of going to the bond market for a few years).

Why have the Eurozone countries agreed to lend money to Greece before it defaults? Would it not be better to have the default (or rescheduling if you prefer) first and then offer guarantees for new borrowing?

That would work a bit like the Brady bonds issued following the Latin American defaults in the 80s. The US guaranteed the Bradies which were backed by debtor country assets and IMF receipts.

See Wikipedia for more on Bradies.