In the solution of the problems distinctive of the second step, the commander starts with a consideration of the salient features of a favorably progressing military operation. This procedure is appropriate because any series of these problems, considered as a whole, pertains to the single problem of determining the most effective operation, or series of operations, for carrying his basic Decision into effect. If the action contemplated in the basic Decision is of such a nature as to call for successive included efforts in more than one stage, the commander limits his consideration, should he find such restriction advisable on sound grounds, to the operation or operations included in the first stage. * * * * * On this basis, the commander considers, first, the feature of correct physical objectives. He has first to determine what his correct physical objectives will be. This determination may or may not present a perplexity. Frequently, the procedure of the first step (Chapter VI) will have plainly indicated one or more, perhaps all, of the physical objectives involved. In some cases, also, the basic Decision will have plainly pointed out the action to be taken, and with respect to what physical objectives. In these instances, the commander may, with little further analysis or none, set down the operations which he considers necessary or desirable with respect to these physical objectives. In other cases, however, the action indicated in the Decision, though plainly indicating the commander's intent--that is, his calculated line of endeavor--may not have designated the numerous physical objectives as to which his effort is to be exerted. For example, the Decision "to interrupt enemy trade on the southern maritime routes" is quite clear, but what are the numerous exertions of force required, and with relation to what physical objectives? Immediately there is a perplexity. Guided by the analysis made in his previous estimate of the situation, the commander now determines what the physical objectives are, action as to which will contribute to the accomplishment of the effort. The sum total of the actions taken against these physical objectives is properly equivalent to the accomplishment of the action indicated in his Decision. He may not be able at this time to determine all of the correct physical objectives, but he can determine certain correct ones (for the method, see Section III of Chapter IV).