Yeah,
that is a pearler BG. How can a government guarentee so much value???????
They can't.
But they can guarentee something that is much less valuable (and that will be your cash in 2-3 years).
People are going on about house prices falling. but its all relative; they'll only 'really' fall if the real value of our money doesn't fall faster.
A guarentee on money means that it has already been devalued.