We have done all that, but lots of people like you say because it's not perfect, you've done nothing and therefore I'm walking away from it – it's pa… - Tony Blair

I've never claimed to have a monopoly of wisdom, but one thing I've learned in this job is you should always try to do the right thing, not the easy thing. Let the day-to-day judgments come and go: be prepared to be judged by history.

The first rule in politics is that there are no rules, at least not in the sense of inevitable defeats or inevitable victories. If you have the right policy and the right strategy, you always have a chance of winning. Without them, you can lose no matter how certain the victory seems.

But then, second, there are the changes of a systemic nature – reform of healthcare, welfare, privatisation of a major state utility, for example – and these changes involve painstaking analysis of the system, the precise changes you want to make and their relationship to the system as it currently operates; they involve managing a range of different interests, all of which will fight the change or find ways to diminish or neuter it.