A second point of view which must not be neglected is precisely that which Zelter rightly emphasizes. A great end cannot be attained except by staking large intellectual and material resources, and no certainty of success can ever be anticipated. Every undertaking implies a greater or less venture. The daily intercourse of civic life teaches us this lesson; and it cannot be otherwise in politics where account must be taken of most powerful antagonists whose strength can only be vaguely estimated. In questions of comparatively trifling importance much may be done by agreements and compromises, and mutual concessions may produce a satisfactory status. The solution of such problems is the sphere of diplomatic activity. The state of things is quite different when vital questions are at issue, or when the opponent demands concession, but will guarantee none, and is clearly bent on humiliating the other party. Then is the time for diplomatists to be silent and for great statesmen to act. Men must be resolved to stake everything, and cannot shun the solemn decision of war. In such questions any reluctance to face the opponent, every abandonment of important interests, and every attempt at a temporizing settlement, means not only a momentary loss of political prestige, and frequently of real power, which may possibly be made good in another place, but a permanent injury to the interests of the State, the full gravity of which is only felt by future generations. Not that a rupture of pacific relations must always result in such a case. The mere threat of war and the clearly proclaimed intention to wage it, if necessary, will often cause the opponent to give way. This intention must, however, be made perfectly plain, for "negotiations without arms are like music-books without instruments," as Frederick the Great said. It is ultimately the actual strength of a nation to which the opponent's purpose yields. When, therefore, the threat of war is insufficient to call attention to its own claims the concert must begin; the obligation is unconditional, and the _right_ to fight becomes the _duty_ to make war, incumbent on the nation and statesman alike.