More from Gray:
So What! The Meaning of Strategy
You probably will not prove able to fight your way out of the waging of the wrong war. To be fair to bold policymakers, one must conclude that often it will not be at all obvious ahead of time just how fickle the gods of war can prove themselves to be. However, it can surely be no secret that a decision to wage war, almost any war at any time and in any environment, will be a gamble. Also, war is different from all else in the human historical narrative.
And always, Clausewitz:
Why strategy is difficult
Competence cannot offset folly along the means-ends axis of strategy. Military history is littered with armies that won campaigns in the wrong wars.
Since the future is unforeseeable--do not put faith in the phrase "foreseeable future"--we must use only assets that can be trusted. Specifically, we plan to behave strategically in an uncertain future on the basis of three sources of practical advice: historical experience, the golden rule of prudence (we do not allow hopes to govern plans), and common sense. We can educate our common sense by reading history. But because the future has not happened, our expectations of it can only be guesswork. Historically guided guesswork should perform better than one that knows no yesterdays. Nonetheless, planning for the future, like deciding to fight, is always a gamble.
The first, the supreme, the most far-reaching act of judgement that the statesman and commander have to make is to establish by that test [of war as an instrument of policy] the kind of war on which they are embarking; neither mistaking it for, nor trying to turn it into, something that is alien to its nature. This is the first of all strategic questions and the most comprehensive.
No one starts a war-- or rather, no one in his senses ought to do so-- without first being clear in his mind what he intends to achieve by that war and how he intends to conduct it.