Authors of books that reveal secrets from past wars have to be careful. Their aim might be to recognise the work and efforts of a forgotten group of people but they then open up the whole issue of why such work has been kept secret for so long.

Here we have a group of people, starting out small in a single office in an anonymous building in London but later being able to to commandeer huge estates almost at will and having access to resources denied other parts of the military. This was the group of people who were to steer Britain's 'guerrilla' activities during the Second World War.

However, when a state carries out such activities it is presented with questions of morality and whether there's any obligation to adhere to international conventions that the state might have adopted and to which it expected other states to comply. Although Milton introduces these matters his acceptance of the work of the secret sections (which became the fore runners of later anti-Communist and anti-liberation activities by MI6 in the UK and the CIA in the United States) means that he shies away from any conclusion.

In many senses this was due to the justification that arose from the idea that Hitlerite fascism was so insidious any means to destroy it were valid. But that had to be 'killed' in the post war years as such approaches to the Cold War were institutionalised and made even more obscure to the general public. Something which Milton doesn't seem to consider.

Another comment upon British society of the 1930s is made when Milton describes how MD1 (the name given to this fledgling forerunner of MI6) depended upon 'the old boys network', where representatives of the ruling class were the preferred candidates for the job. Outsiders from that world only got through the net if they demonstrated a particular genius in one field or another.

It only appears as a bit of a throwaway but I found interesting that this secret group, very much under the wing of Churchill, played around with the use of biological weapons. The sensitivity of this matter means that any pieces of paper relating to such suggestions have been well hidden or destroyed. However, it's telling that Churchill is mentioned as having sanctioned the use of such weapons in the war of intervention in Russian against the Russian Bolsheviks as well as in the 'North West Frontier'.

I think that Milton very much over emphasises the importance of this group of saboteurs and assassins. Yes they did play a part in some major coups – the assassination of Reinhard Heydrich in Prague being one case (the Czech patriots being badly served in a recent film of the events) – but the war was won by the efforts of millions of people throughout the world. Even though attacks organised from London might have played a role it was on the battlefields of Stalingrad and Kursk that the war was won.

Finally I liked the part at the end when the value of well organised sabotage in the destruction of factories forced to produce for the Nazis was more productive than the indiscriminate bombing of civilian populations favoured by the murderous 'Bomber' Harris.