Once Saddam had used Chemical weapons on his own people he had to go. If not for the good of his own people, for the good of the rest of the world. Iraq would have become a target for the likes of ISIS and had WMD fallen into their hands, god help all of us. He could not be allowed to remain. As for cost, Blair did what he believed was right by our country and by others, the cost will probably be many sleepless nights with a pletora of thoughts going on inside his head. Believe me, is one of the worst possible punishments a man can have. It's not something money can cure, only alcohol or drugs can temporarily nul the pain, both of which detract from the quality of life. Death is the only real release.
Yes, the aftermath was badly planned or ignored and hence, has ended badly. However, with WMD in the hands of a terrorist group, it could be much much worse. Who knows how much worse it could have been?
Looking at the bigger picture, the action of the US and the UK might actually put-off other dictators using WMD on their own people, as surely, they should realise that it will mark the beginning of the end for their rule. This must be a good thing. The death of David Kelly was sad, but not a world changing event for anyone except his close family and friends. As far as I can see, Blairs' major failure was failing to equip the British forces adequately. He will have to live with that for the rest of his days. Guilt is a horrendus feeling, it can only be cured by the forgiveness of those who have been hurt and I don't see the families of the troops killed in Iraq forgiving him some time soon. I think you will see Tony Blair dying a very sad old man.
