The Hindenburg line!—­and the two tanks!  The combination, indeed, suggests the whole story of that final campaign in which the British Army, as the leading unit in a combination of armies brilliantly led by a French Generalissimo whom all trusted, brought down the military power of Germany.  There were some six weeks of fighting after the capture of the Hindenburg line; but it was that capture—­“the essential part” of the whole campaign, to use Marshal Haig’s words—­to which everything else was subordinate, which, in truth, decided the struggle.  And the tanks are the symbol at once of the general strategy and the new tactics, by which Marshal Foch and Sir Douglas Haig, working together as only great men can, brought about this result, bettered all that they had learned from Germany, and proved themselves the master minds of the war.  For the tanks mean surprise—­mobility—­the power to break off any action when it has done its part, and rapidly to transfer the attack somewhere else.  Behind them, indeed, stood all the immense resources of the British artillery—­guns of all calibres, so numerous that in many a great attack they stood wheel to wheel in a continuous arc of fire.  But it was the tanks which cleared the way, which flattened the wire, and beat down the skill and courage of the German machine gunners, who have taken such deadly toll of British life during the war.  And behind the tanks, protected also by that creeping barrage of the great guns, which was the actual invention of that famous Army Commander with whom I had spent an evening at Valenciennes, came the infantry lines, those now seasoned and victorious troops, for whose “stubborn greatness in defence,” no less than their “persistent vigour” and “relentless determination” in attack, General Haig finds words that every now and then, though very rarely, betray the emotion of the great leader who knows that he has been well and loyally served.  There is even a certain jealousy of the tanks, I notice, among the men who form the High Command of the Army, lest they should in any way detract from the credit of the men.  “Oh, the tanks—­yes—­very useful, of course—­but the men!—­it was the quality of the infantry did it.”

All the same, the tanks—­or rather these tell-tale marks beside this front trench of the Hindenburg line, together with that labyrinth of trenches, cut by the Canal du Nord, which fills the whole eastern scene to the horizon—­remain in my mind as somehow representative of the two main facts which, according to all one can read and all one can gather from the living voices of those who know, dominated the last stage of the war.

For what are those facts?

First, the combination in battle after battle, on the British front, of the strategical genius, at once subtle and simple, of Marshal Foch, with the supreme tactical skill of the British Commander-in-Chief.