Upon this question certain things need to be said very plainly.  The decisive factor in the sort of war we are now waging is production and right use of mechanical material; victory in this war depends now upon three things:  the aeroplane, the gun, and the Tank developments.  These—­and not crowds of men—­are the prime necessity for a successful offensive.  Every man we draw from munition making to the ranks brings our western condition nearer to the military condition of Russia.  In these things we may be easily misled by military “experts” We have to remember that the military “expert” is a man who learnt his business before 1914, and that the business of war has been absolutely revolutionised since 1914; the military expert is a man trained to think of war as essentially an affair of cavalry, infantry in formation, and field guns, whereas cavalry is entirely obsolete, infantry no longer fights in formation, and the methods of gunnery have been entirely changed.  The military man I observe still runs about the world in spurs, he travels in trains in spurs, he walks in spurs, he thinks in terms of spurs.  He has still to discover that it is about as ridiculous as if he were to carry a crossbow.  I take it these spurs are only the outward and visible sign of an inward obsolescence.  The disposition of the military “expert” is still to think too little of machinery and to demand too much of the men.  Behind our front at the time of my visit there were, for example, many thousands of cavalry, men tending horses, men engaged in transporting bulky fodder for horses and the like.  These men were doing about as much in this war as if they had been at Timbuctoo.  Every man who is taken from munition making at X to spur-worshipping in khaki, is a dead loss to the military efficiency of the country.  Every man that is needed or is likely to be needed for the actual operations of modern warfare can be got by combing out the cavalry, the brewing and distilling industries, the theatres and music halls, and the like unproductive occupations.  The under-staffing of munition works, the diminution of their efficiency by the use of aged and female labour, is the straight course to failure in this war.

In X, in the forges and machine shops, I saw already too large a proportion of boys and grey heads.

War is a thing that changes very rapidly, and we have in the Tanks only the first of a great series of offensive developments.  They are bound to be improved, at a great pace.  The method of using them will change very rapidly.  Any added invention will necessitate the scrapping of old types and the production of the new patterns in quantity.  It is of supreme necessity to the Allies if they are to win this war outright that the lead in inventions and enterprise which the British have won over the Germans in this matter should be retained.  It is our game now to press the advantage for all it is worth.  We have to keep ahead to win.  We cannot do so unless we have unstinted men and unstinted material to produce each new development as its use is realised.