4. This is not to exclude the plan of using four or six British divisions in these great initial operations. Such a force is a material factor of significance. Its value to the French would be out of all proportion to its numerical strength. It would encourage every French soldier and make the task of the Germans in forcing the frontier much more costly. But the question which is of most practical consequence to us is what is to happen after the frontier has been forced and the invasion of France has begun. France will not be able to end the war successfully by any action on the frontiers. She will not be strong enough to invade Germany. Her only chance is to conquer Germany in France. It is this problem which should be studied before any final decision is taken. 5. The German armies in advancing through Belgium and onwards into France will be relatively weakened by all or any of the following causes:— By the greater losses incidental to the offensive (especially if they have tested unsuccessfully the French fortress lines); By the greater employment of soldiers necessitated by acting on exterior lines; By having to guard their communications through Belgium and France (especially from the sea flank); By having to invest Paris (requiring at least 500,000 men against 100,000) and to besiege or mask other places, especially along the seaboard; By the arrival of the British army; By the growing pressure of Russia from the thirtieth day; And generally by the bad strategic situation to which their right-handed advance will commit them as it becomes pronounced. All these factors will operate increasingly in proportion as the German advance continues and every day that passes. 6. Time is also required for the naval blockade to make itself felt on German commerce, industry, and food prices, as described in the Admiralty Memorandum, and for these again to react on German credit and finances already burdened with the prodigious daily cost of the war. All these pressures will develop simultaneously and progressively. [The Chancellor of the Exchequer has drawn special attention to this and to the very light structure of German industry and economic organisations.] 7. By the fortieth day Germany should be extended at full strain both internally and on her war fronts, and this strain will become daily more severe and ultimately overwhelming, unless it is relieved by decisive victories in France. If the French army has not been squandered by precipitate or desperate action, the balance of forces should be favourable after the fortieth day, and will improve steadily as time passes. For the German armies will be confronted with a situation which combines an ever-growing need for a successful offensive, with a battle-front which tends continually towards numerical equality. Opportunities for the decisive trial of strength may then occur.