So what are these inquiries for?
Like the investigations into maritime accidents (in which we have a greater interest), the search for the truth about the Iraq war has been a process in need of several re-iterations  - each of them having left the public dissatisfied.
Confronted with the horrid necessity of having to satisfy people’s curiosity and diffuse various social tensions, governments are not inimical to the idea of setting up public inquiries, but, if there is any risk of political humiliation, they make sure that these affairs will not seek out the truth in earnest or learn any lessons from it – except, perhaps, on how to circumvent the facts more effectively next time around.
As it can be said about many other similar undertakings before it, the Chilcot inquiry could have easily not existed . Since many in the political Establishment know only too well what really happened and who is to blame and why, it would have been a lot easier (and cheaper) if the truth had been publicly revealed, without too much ceremony and vacillation, and the appropriate corrective/retributive actions had then been taken as required.
But discovering the truth is not what a public inquiry is about. Is it? A public inquiry, nowadays, is more like a communal bath – a public place of sensual abandonment and ritual lustration - where the interested parties, hiding their nudity from the public behind clouds of steam and odorous suds, soak together in opulent lather, scrubbing each other’s backs. Its purpose is simply to make them appear purer in the end, and leave them more relaxed - and smelling of flowers.
 See the Hutton inquiry and the Butler review
 Just as the MV Derbyshire, FV Gaul and FV Trident opened and re-opened formal investigations