But the continued improvement in the means of communication during the nineteenth century presently upset that situation, and so presently began to neutralise the geographical quarantine which had hedged about these communities that were inclined to let well enough alone. The increasing speed and accuracy of movement in shipping, due to the successful introduction of steam, as well as the concomitant increasing size of the units of equipment, all runs to this effect and presently sets at naught the peace barriers of sea and weather. So also the development of railways and their increasing availability for strategic uses, together with the far-reaching coordination of movement made possible by their means and by the telegraph; all of which is further facilitated by the increasing mass and density of population. Improvements in the technology of arms and armament worked to the like effect, of setting the peace of any community on an increasingly precarious footing, through the advantage which this new technology gave to a ready equipment and a rapid mobilisation. The new state of the industrial arts serviceable for warlike enterprise put an increasingly heavy premium on readiness for offense or defense, but more particularly it all worked increasingly to the advantage of the offensive. It put the Fabian strategy out of date, and led to the doctrine of a defensive offense. Gradually it came true, with the continued advance in those industrial arts that lend themselves to strategic uses, and it came also to be realised, that no corner of the earth was any longer secure by mere favor of distance and natural difficulty, from eventual aggression at the hands of any provident and adventurous assailant,--even by help of a modicum of defensive precaution. The fear of aggression then came definitively to take the place of international good-will and became the chief motive in public policy, so fast and so far as the state of the industrial arts continued to incline the balance of advantage to the side of the aggressor. All of which served greatly to strengthen the hands of those statesmen who, by interest or temperament, were inclined to imperialistic enterprise. Since that period all armament has conventionally been accounted defensive, and all statesmen have professed that the common defense is their chief concern. Professedly all armament has been designed to keep the peace; so much of a shadow of the peaceable bias there still stands over.