Unless our defending fleet knew with reasonable sureness, however, the location, speed, and direction of motion of the coming fleet, so that it could make its dispositions for attack, it would hardly desire to meet the enemy at night, unless it were confident that it would meet the train and not the main fleet or the destroyers. Night attacks, both on sea and land, are desirable, if the attacker can inflict surprise on the attacked, and not be surprised himself. In the darkness a flotilla of destroyers may make an attack on the various vulnerable colliers and supply vessels of a fleet, or even on the main body, and achieve a marked success, because that is the rôle they are trained to play. But the tremendous power and accuracy of battleships cannot be utilized or made available in darkness; and therefore a commander-in-chief, anxious to defeat by superior skill a coming fleet larger than his own, would hardly throw away all chance of using skill by risking his main body in a night encounter. Every operation planned by strategy is supposed to result from the "decision" which follows the estimate of the situation; even if in some simple or urgent cases, the decision is not laboriously worked out, but is almost unconscious and even automatic. Now, it is hardly conceivable that any estimate of the situation would be followed by a decision to go ahead and trust to luck, except in very desperate circumstances. In such circumstances, when hope is almost gone, a desperate blow, even in the dark, may save a situation--as a lucky hand at cards may redeem a gambler's fortune at even the last moment. But strategy is opposed to taking desperate measures; and pugilists and even gamblers recognize the fact that when a man becomes "desperate," his judgment is bad, and his chances of success are almost zero. While it is possible, therefore, that the main bodies of hostile fleets may come together in the night, we may assume that it will not be as part of any planned operations, and therefore not within the scope of this discussion; and that any combat which may result will be one in which strategy will play no part, and in which even tactics will yield first place to chance. But while our defending fleet will have to base most of its decisions on guesses, the coming fleet, on the other hand, having accepted the strategical disadvantage of leaving its base far in rear, will advance with all the advantage of the offensive, especially in knowing where it intends to go and what it desires to do. Coming over on a definite mission it will have been able to know what preparations to make; and as the naval Powers of Europe understand the need of co-ordination between policy and strategy, the fleet will doubtless have had time to make those preparations; it will not have started, in fact, and war will not have been declared, until all those preparations have been made.