The official biographers of H. H. Asquith believed that his sole difference of any importance with Sir Henry Campbell-Bannerman in the period when Asquith served as his principal lieutenant rose in connexion with the Trade Disputes Act of 1906. In fact, another important difference divided them in the following spring, this one rising out of their respective views on the proper mode of limiting the veto of the house of lords. That of Campbell-Bannerman is well known. He sponsored a plan of suspensory veto that could conceivably limit the period in which the lords' veto operated to little more than six months. Under its terms a bill sent up to the house of lords would go to a small conference representing each house equally when the two houses were in disagreement. Should the conference fail, the bill or another like it could be reintroduced in the house of commons after an interval of at least six months, passed under drastic closure, and sent once more to the house of lords. The impasse continuing, a second conference might be held; and a second failure at this juncture could entail a repetition of the whole process. But if a third conference proved unsuccessful, the bill could become law without the consent of the house of lords. Known subsequently as the C-B veto plan, it was made public by the Prime Minister in a speech in the house of commons, on 24 June 1007, when he also introduced and carried by a large majority a resolution asserting that the power of the house of lords to alter or reject bills should be so restricted by law as to secure that the decision of the house of commons should prevail within the limits of a single parliament.

Modern technical and scientific development has altered war from a contest between men into a combat between machines. Even the development of firearms did not bring about a change of this magnitude, since firearms went into combat propelled by animal energy (of man and beast). This change-over occurred first at sea when steam engines started to propel ships of war. In days of sail at sea a great deal depended on the purely human factor of seamanship. With the introduction of ships moved by machinery all came depend on the quality and power of this machinery. Drake, De Ruyter Nelson, with all their skill or experience, could have done nothing against steam man-of-war. On land this development took longer. Throughout nineteenth century railways carried men and beasts to the scene of combat and brought them their supplies, but on the battlefield men and horses carried the weapons of war into battle. The invention of the petroleum-driven internal combustion engine changed all that. For the first time man commanded the power necessary to propel engines freely over land and in the air, an invention which had already occupied the imagination of Leonardo da Vinci and appeared in the prophetic writings of Jules Verne and H. G. Wells.