The southern half of the North Sea--say, roughly from Peterhead to the Skagerack, 400 miles; from the Skagerack to Heligoland, 250; from Heligoland to Lowestoft, 300; and from Lowestoft to Peterhead, 350 miles--was left as a kind of no man’s land. If the Germans chose to cruise about in this area, they took the chance of being cut off and engaged by the British forces, whose policy it was to leave their bases from time to time for what Sir John Jellicoe in the Jutland despatch describes as “periodic sweeps through the North Sea.” But the German Fleet being supplied with Zeppelins, could, in weather in which Zeppelins could scout, get information so far afield as to be able to choose the times for their own cruises in the North Sea, and so make the procedure a perfectly safe one, so long as chance encounters with submarines and straying into British mine-fields could be avoided. Thus for the old policy of close blockade was substituted a new one, that of leaving the enemy a large field in which he might be tempted to manœuvre; and it had this value, that should he yield to the temptation, an opportunity must sooner or later be afforded to the British Fleet of cutting him off and bringing him to action. Meantime he was cut off from any large adventure far afield. He would have to fight for freedom. It gave, so to speak, the Germans the chance of playing a new sort of “Tom Tiddler’s ground.” The point to bear in mind is, that it left the Germans precisely the same freedom to seek or avoid action as the armies of antiquity possessed. Thus no naval battle could be expected unless--as Colin says--the weaker wished to fight, or was cornered or surprised. Now, against surprise, the German Fleet was seemingly protected by Zeppelins. It could hardly be cornered unless, in weather in which aerial scouting was impossible, it was tempted to some great adventure--such as the despatch of a raiding force to invade--which would enable a fast British division to get between this force and its base. So that the chance of a fleet action really turned upon the Germans being willing to fight one. And they could not be expected to be anxious for this. “A war,” says Colin, “is always slow in which we know that the battle will be decisive, and it is so important as to be only accepted voluntarily.” The state of relative strength in May, 1916, was not such as to afford the Germans the slightest hope of a decisive victory if it brought the whole British Fleet to action. Nor was the naval situation such that there was any stroke that Germany could execute if it could hold the command of some sea passage for twenty-four hours or so. There was nothing it could expect to achieve if, by defeating or at any rate standing off one section of the British Fleet, it could enjoy a brief local ascendancy.