Is Greece's crumbling economy in dire straits because of austerity cuts?
In part, yes. Greece is in trouble for four reasons:
1) they spent too much and ran up too much external debt.
2) they don't control their own currency, so they can't use monetary policy to ease the pain.
3) the other EU countries control their fiscal policy now, and those countries would rather see a million Greeks impoverished than a single German or French lose their jobs - because Germans vote in Germany, not Greece.
4) the policies being enforced by these outside nations (austerity) are causing the economy to crash even deeper because the private sector won't invest a wooden nickel in an economy without the support of it's own government.
Britain meets zero of those reasons.