Prime Minister to General Ismay, for C.O.S. Committee
19.IX.40
(Admiral Phillips to see)
1. It was not solely on moral grounds that we decided against retaliation upon Germany. It pays us better to concentrate upon limited high-class military objectives. Moreover, in the indiscriminate warfare the enemy's lack of skill in navigation, etc., does not tell against him so much.
2. However, the dropping of large mines by parachute proclaims the enemy's entire abandonment of all pretence of aiming at military objectives. At five thousand feet he cannot have the slightest idea what he is going to hit. This therefore proves the "act of terror" intention against the civil population. We must consider whether his morale would stand up to this as well as ours. Here is a simple war thought.
3. My inclination is to say that we will drop a heavy parachute mine on German cities for every one he drops on ours; and it might be an intriguing idea to mention a list of cities that would be black-listed for this purpose. I do not think they would like it, and there is no reason why they should not have a period of suspense.
4. The time and character of the announcement is a political decision. Meanwhile I wish to know when the tackle could be ready. Let care be taken to make a forthcoming response to this. Let officers be set to propose the best method on a substantial scale in the shortest time. It would be better to act by parachute mines upon a number of German towns not hitherto touched, but if we have to use 1,000-lb air-bombs which we have because otherwise the delay would be too long, let the case be stated.
5. I wish to know by Saturday night what is the worst form of proportionste retaliation, i.e., equal retaliation, that we can inflict upon ordinary German cities for what they are now doing to us by means of the parachute mine. To-day we were informed that thirty-six had been dropped, but by to-morrow it may be one hundred. Well, let it be a hundred, and make the best plan possible on that scale for action within, say, a week or ten days. If we have to wait longer so be it, but make sure there is no obstruction.
6. Pending the above information I agree that we should not make a wail or a whine about what has happened. Let me have practical propositions by Saturday night.