Sixty-‐nine years ago, Bernard Brodie published his famous precept about the consequences of the atomic bomb:
“Thus far the chief purpose of our military establishment has been to win wars. From now on its chief purpose must be to avert them. It can have almost no other useful purpose.”1
Brodie was well ahead of his time (until the 1960s the US had the weapons to “win” a war with the USSR, although it would have been costly). But the problem he posed went far beyond the purposes of a military establishment and it continually challenges our statecraft. To solve it with general principles would require having the Erised mirror of Harry Potter, which reflected not a viewer’s image but rather his heart’s desire. Harry saw his parents; his friend Ron saw himself winning a sports event. A nuclear force planner would see a general principle, a guide to policy and force planning,
a formula to tell enemies and allies (and ourselves) about the military contingencies that might arise if events unfolded along certain lines.
But we don’t have one.