Would back office systems cope?

When we were at Sibos we enjoyed a team dinner in a local restaurant. As the topics of the day were mulled over somewhere up popped a contentious question "If
 the Greeks default, and Greece disengages from EUR and reverts to the GDR,
would back office systems cope"? As the discussion raged back and forth,
buoyed by the odd jar or two, it struck me that every point supporting the view
that systems wouldn't cope was not about the system itself, it was a people,
practicality or political issue. New currencies have been added and deleted
to/from the ISO list since its inception and its nothing new for the shiny new
button in the trading room to calmly advise the back office that he's just
entered into a financial instrument requiring the settlement of a new currency.

If a bank doesn't have a correspondent relationship within the designated country
it would rapidly send out RFI's and begin making them, and if that's not the
route they required I'm sure the big global multi-nostro clearers will be happy
for additional business. Let’s be clear the default and subsequent fall out to
the Drachma would not happen over-night, there would be a tactical withdrawal
with a period of change. Yes, there are practicalities to overcome, yes, there
are people and infrastructure changes required, but can the system cope,
absolutely. It’s just another currency.