Tony Blair seems to want us to forgive any damage he did because he meant well and believed what he was doing was right.
We should reject this line of reasoning. It is outcomes, not intentions which matter.
One of the more famous quotations from Adam Smith is:
It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their self-love, and never talk to them of our own necessities but of their advantages.
This is a superb, simple example of how selfish motives leads to good outcomes - thanks to the self-love of the baker we have bread to buy and eat. We feed ourselves thanks to the self-love of the producers and their desire to make a profit and increase their wealth.
The converse is the many well meaning actions which lead to bad outcomes.
For example, we are bombarded with demands that more aid money should be given to foreign governments. The idea is well meaning, we are told it will help alleviate poverty and aid development. In reality it often hinders development and leads to corruption and rent seeking. Money goes to the government who spend it on their own interests and on increasing the size of the state, at the expense of the entrepreneur who works to build a business. It becomes easier to gain wealth through political favour, which leads to less investment and the spread of wealth through job creation and more concentration of wealth in the political elite.
As for believing you’re doing the right thing. It should be clear to anyone with an ounce of sense that that is never justification except perhaps to yourself.
Believing something to be true does not make it true.
Belief or well meaning do not justify actions. The actions may have good outcomes, they may be justifiable on other grounds, but simply believing you’re doing the right thing is not enough.

