he observed that the principle of concentration had become "a kind of shibboleth" that had done more harm than good. The principle of concentration is "a truism—no one would dispute it. As a canon of practical strategy, it is untrue". Corbett felt that superior concentration thus not only deterred the weaker opponent from seeking battle but presented him with an opportunity to attack his enemy's exposed national lines of communication. Corbett felt that superior concentration of naval forces created yet another serious problem. The greater the concentration of a fleet, the more difficult it was to conceal its whereabouts and movements. In the process of adapting Clausewitz's theory to the unique circumstances of naval warfare, Corbett developed his own innovative theory of limited war in maritime strategy. The first of his two main points was that in wartime conditions on the continent, as opposed to those in the maritime and imperial environment, wars were fought mostly between adjacent states. Corbett's second point was that in wars between contiguous continental states "there will be no strategical obstacle to his [the enemy's] being able to use his whole force". In other words, the nature of continental war makes it difficult to limit political aims, because one or both states are able to use all of the means at their disposal to protect the inevitably threatened vital interests. As Corbett demonstrated, this means that the conditions for the ideal limited war exist only in maritime warfare and can only be exploited by the preponderant naval power: " … limited war is only permanently possible to island Powers or between Powers which are separated by sea, and then only when the Power desiring limited war is able to command the sea to such a degree as to be able not only to isolate the distant object, but also to render impossible the invasion of his home territory." Like Clausewitz, Corbett shared a belief in the primacy of politics in war and in devising an appropriate strategy to protect the national interests. However, Corbett was interested in the diplomatic alliance systems and coalitions formed before and during a war, and he was concerned with the economic and financial dimensions of waging war as well as with the technological and material aspects of war, which were of no interest to Clausewitz. Works of enduring value Corbett's value for today's military professional lies in four of his