SJPONeill asked two questions, I can only offer an explanation for the first:
Quote Originally Posted by SJPONeill View Post
This should be a damn good read but two questions...

Why, oh why will they not let serving officers contribute? This is so short-sighted and having followed a number of senior British officers' public comments over the last 4-5 years, I can not imagine that the blocked contributions to this book could be that damaging to the Blair or the current administration.
British officialdom is rarely open to public servants, at all levels, contributing on contemporary public issues - I exclude "whistle-blowing". This policy has been reinforced by politicians reluctance to have informed "insider" contributions, which often are contrary to the "spin" the public and media are fed with.

The UK Secretary of Defence, Philip Hammond, made it very clear from taking office that public comments had to be approved and "on message".

What happened to two 'lessons learned' internal unclassified reviews of British military performance provide some insight. The 'Operation Banner' review on Northern Ireland appeared in public via a Republican-leaning group (IIRC it is linked here) and that on Iraq remains an official document - partly I suspect as the Official Iraq Inquiry (known as the Chilcot Report) has yet to be published.

Historians often attest to the value of combing US National Archives for UK documents.