However, more momentous situations are also to be expected. These will present new problems for the commander to solve. Such new problems, so long as they do not challenge the integrity of the basic plan, will not prevent the competent commander from proceeding with his predetermined effort if he takes appropriate action in due time to control the unfolding situation. To maintain such control may call for the exercise of outstanding qualities of the mind and of the will. For example, it is assumed that the commander's basic Decision was to destroy an enemy convoy, the purpose of the Decision being to prevent the convoy from reaching its destination. Now, it is supposed that, during the supervision of the action planned for the destruction of the enemy convoy, the commander receives information of a hostile reinforcement. It is further supposed that this reinforcement, if it joins the enemy convoy's escort, can jeopardize the success of the basic plan. The commander is now confronted with a serious situation which, if not controlled by action of the right kind, at the right time, and at the right place, may result in shattering his basic plan. However, if the commander takes action along correct lines in due time, he can still preserve the integrity of his basic plan and so continue to control the shaping of the situation. Having re-examined his solution of his basic problem and found it sound, the commander finds himself under the necessity of resolving a perplexity as to what to do about the enemy reinforcement. In this case, he concludes that his proper action is to prevent the enemy reinforcement from protecting the convoy. This task, self-assigned because of the demands of the situation, becomes the basis for the mission of his new problem, the mission being:-- (Task) To prevent the enemy reinforcements from protecting the convoy, (Purpose) in order to contribute to the eventual destruction of the convoy. The commander now considers the various courses of action open to him for the accomplishment of this mission. He also considers the enemy courses of action. He then considers each of the former in relation to each of the latter. He compares, on this basis, each of his retained courses of action with the others and so selects the best course of action. Finally, he arrives, in this manner, by the same process as in a basic problem (Chapter VI), at a decision as to the best course of action. Should this decision be to sink the enemy reinforcement, its statement linked to its purpose, would be:-- To destroy the enemy reinforcement, in order to prevent it from protecting the convoy. Problems Challenging the Integrity of the Basic Plan