The Germans alone have made any sustained attempt to strike through the air at their enemies beyond the war zone. Their Zeppelin raids upon England have shown a steadily increasing efficiency, and it is highly probable that they will be repeated on a much larger scale before the war is over. Quite possibly, too, the Germans are developing an accessory force of large aeroplanes to co-operate in such an attack. The long coasts of Britain, the impossibility of their being fully equipped throughout their extent, except at a prohibitive cost of men and material, to resist air invaders, exposes the whole length of the island to considerable risk and annoyance from such an expedition. It is doubtful, though, if the utmost damage an air raid is likely to inflict upon England would count materially in the exhaustion process, and the moral effect of these raids has been, and will be, to stiffen the British resolution to fight this war through to the conclusive ending of any such possibilities. The net result of these air raids is an inflexible determination of the British people rather to die in death grips with German militarism than to live and let it survive. The best chance for the aircraft was at the beginning of the war, when a surprise development might have had astounding results. That chance has gone by. The Germans are racially inferior to both French and English in the air, and the probability of effective blows over the deadlock is on the whole a probability in favour of the Allies. Nor is there anything on or under the sea that seems likely now to produce decisive results. We return from these considerations to a strengthened acceptance of Bloch. The essential question for the prophet remains therefore the question of which group of Powers will exhaust itself most rapidly. And following on from that comes the question of how the successive stages of exhaustion will manifest themselves in the combatant nations. The problems of this war, as of all war, end as they begin in national psychology. But it will be urged that this is reckoning without the Balkans. I submit that the German thrust through the wooded wilderness of Serbia is really no part of the war that has ended in the deadlock of 1915. It is dramatic, tragic, spectacular, but it is quite inconclusive. Here there is no way round or through to any vital centre of Germany's antagonists. It turns nothing; it opens no path to Paris, London, or Petrograd. It is a long, long way from the Danube to either Egypt or Mesopotamia, and there--and there--Bloch is waiting. I do not think the Germans have any intention of so generous an extension of their responsibilities. The Balkan complication is no solution of the deadlock problem. It is the opening of the sequel.