The banking bailout was pretty much essential, it's a bit like not being able to pay your credit card and the effect that has on your credit rating.
What wasn't essential is that everyone who helped promote the problem should remain in a similar role post bailout.
The subsequent pain, as HMG slashes various budgets, was bound to come at some point - the only real issue is where the limited cash should have gone, and it seems bizarre to me to ensure we retain the ability to intervene overseas in far off places but not to retain an effective defence of the UK itself.
I can only presume that Cameron etc believe that a Chinook full of SAS troopers is all it will take to fend off any future aggressor....I think he's been watching 'Ultimate Force' a bit too often.