As far back as February, 1918, pressure was brought to bear on the French Authorities to agree to defined measures to meet the emergency of a withdrawal of part of our line, which was then foreseen as a probability. But it was not found possible to secure prompt assent to the steps which were necessary. There were all sorts of complications. For one thing it was feared that to set up the machinery of evacuation would spread dismay among the French civilians. Another obstacle was the financial one which I have already mentioned. Yet another was that created by the status of the miners in threatened areas. These were mobilised men under French Military Command; their wives and children were civilians. If their wives and children were evacuated the miners would not stay.
Later, arrangements were agreed to between the British Force and the French Authorities for the systematic evacuation, with their live stock and supplies, of civilians in threatened areas. But the early difficulties considerably hampered operations. I mention this not at all by way of a tilt against the French Authorities, whose reluctance to make provision for evacuations was natural enough, but to show that G.H.Q. was not "caught napping," and to illustrate also the difficulties which an Expeditionary Force operating in a friendly country has to meet.
There are, of course, many advantages springing from the fact that the country in which you are quartered is friendly. But I am not sure that the disadvantages are not almost as great. In an enemy country you know at any rate where you are; military safety, military convenience are the supreme law; and the civilian population have only to be considered to the degree that the laws of war and the dictates of humanity decide. In a friendly country, where the old civil government remains in operation, an Army is hampered at many points. There are various actions which military convenience prompts but which cannot be taken without the assent of the civilian authorities; and perhaps cannot be urged with the weight of the full facts on those civil authorities. This evacuation difficulty is an instance in point. If G.H.Q. had had its way the Germans would have won far less material in their advance; and perhaps their advance would have been stopped at an earlier stage if our operations had not been hampered to some extent by the crowding of the road with civilian refugees.
Still, on the big issues the French were splendid. What, for example, could have been more heroic than the decision they came to a little later: that, in case of the German advance continuing, the whole of the Pas de Calais province was to be destroyed, the harbours of Dunkirk, Calais and Boulogne wrecked, the dykes and locks destroyed so that the country would have been generally inundated?
To some degree defensive inundations were actually carried into effect, but with fresh water only. The responsibility in the main rested with the British Army which was holding the threatened territory. The only saving stipulation made by the French, who thus offered in the cause of the alliance to give up for half a century the use of one of their fairest provinces, was that before the sea was let in to devastate the land, Marshal Foch should give the word. It was on April 12th, 1918, that the Allied Commander-in-Chief gave orders for defensive inundations to stop the Germans from getting to the Dunkirk-Calais region; and on April 13th the Governor of Dunkirk began to put these into effect. There were two schemes of inundation, one for a modified flooding with fresh water of certain limited areas; the other for a general flooding, with sea-water as well as fresh water, of all low-lying areas around Calais and Dunkirk.
It is impossible to praise adequately the stark courage that agreed to this step. It was courage after the antique model, and it showed that France was willing to make any sacrifice rather than allow the wave of German barbarism to sweep over civilisation. The effect of letting the sea in on Pas de Calais and destroying the canal locks and the harbours would have been to make this great province a desert for two generations. The effect of allowing it to fall into German hands, with all its canal and harbour facilities, would have been to give new life to the submarine war, to make the bombardment and ultimately the invasion of the English coast possible.
At one time it seemed almost certain that an evacuation of at least part of Pas de Calais would have to be carried out; and arrangements were made in detail: that in any area which was evacuated, either deliberately or in consequence of direct enemy pressure, the most thorough destruction should be carried out to deny to the enemy any stores of material or facilities of transport. The method of every destruction and the unit responsible for it were arranged in advance.
The main lines of a policy of destruction were laid down in the event of:—
1. A withdrawal to the Calais—St. Omer defensive line;
2. A withdrawal to the line of the Somme;
3. An enemy advance along the line of the Somme, cutting off Flanders and Pas de Calais from the South.