But the forward-looking Denning had also been able to establish the principle that a new sub-section of the NID, the Operational Intelligence Centre,
which replaced the old Movements Section, should receive and coordinate information from all sources.
This had been impossible in the First World War and represented a revolutionary advance.
On the eve of war the OIC stood by with a staff of thirty-six.
They had many problems to overcome, but the main problem of 1939 was that they had virtually no information to coordinate.
Like Tweedledee, the Admiralty could hit out bravely at anything it could see, but it could see very little.
Occasionally, Coastal Command aircraft would catch sight of U-boats, and the RAF had been persuaded to inform the Admiralty when this happened.
Aerial reconnaissance was limited to the hiring of a commercial pilot to take shots of the German coastline.
Information from agents in Europe was 'scanty.
The best … came from a black market dealer in silk stockings with a contact in the German Naval Post Office,
who from time to time was able to give the address of mail for certain ships, thus providing some fragmentary clues to their whereabouts.'