Fred Kaplan writes: The Standard Missile 3, or SM-3 as it’s called, is purely defensive; it works not by blowing up a missile in midair but by slamming into it with great force; in other words, it couldn’t be turned into an offensive weapon, even if some future Western leader wanted it to be.

But from Russia’s point of view, that’s not the issue. As one military adage has it, the only purely defensive weapon is a foxhole, and a battery of antimissile missiles doesn’t change this fact. In the odd world of nuclear strategy, a nation deters an attack by posing a credible threat of “retaliation in kind.” Side A attacks Side B; Side B strikes back against Side A; therefore, Side A doesn’t attack in the first place. But imagine that Side A has an effective missile-defense system. Side A attacks Side B; Side B strikes back, but most of its missiles get shot down before reaching their targets; therefore, Side B is unable to “retaliate in kind.” Both sides do the calculation and understand the strategic imbalance, and therefore (so goes the theory), Side A dominates Side B — intimidates it into doing certain things in A’s favor — without having to go to war.

This is why Russian officials see missile defense systems as a threat. It’s a concept they learned from the Americans. In the 1950s and early ’60s, many American nuclear strategists, notably Herman Kahn, author of the best-seller On Thermonuclear War, advocated anti-ballistic-missile systems as an explicit adjunct to an offensive first-strike strategy: The U.S. launches a nuclear attack on the USSR; the USSR strikes back with the few nuclear missiles that survived the first strike; the U.S. shoots them down with its antimissile missiles. Or, more to the point, the U.S. has the capability to do these things — which puts the U.S. in a dominant position in international confrontations.

In the mid-1960s, when Secretary of Defense Robert McNamara proposed a treaty banning anti-ballistic missiles in the United States and Soviet Union, some Russian officials were puzzled: Why ban defensive weapons, they asked? McNamara schooled them on nuclear strategy; he essentially wanted to avoid the destabilizing situation that Herman Kahn wanted to foster and exploit. The Russians learned the lesson. [Continue reading…]