You wound, like Parthians, while you fly,
And kill with a retreating eye.
Data Point: Palestinians in Gaza sent 120 unguided, short range missiles into Israel in a little over two days last week. Israel's new short range air defense system, Iron Dome, analyzed the trajectory of the missiles and concluded thta only 37 posed a danger to populated areas. It was able to intercept 32 of them. More air defense is coming. Magic Wand, a medium range missile defense system is about to be deployed, and the US just made a special $$ grant to Israel to pay for the expansion of its missile defense system.
Data Point: Offensive air power isn't that effective against these parthian shots. Here's a map of the Israeli air offensive in 2006. They pummeled Lebanon but couldn't stop the missile attacks.
Here's some thinking on this:
- Air defense is expensive. In fixed cost, upkeep cost, and compartive marginal cost (cost of interceptor vs. rocket). Every innovation in attack yields a disproportionate increase in defense costs.
- Air defense against low cost missile attack is mostly psychological. The underlying, evergreen impact of missile barrage is that people are forced to flee to bomb shelters and stay there throughout the attack. This occurs whether there is air defense or not.
- Air defense can provide a false sense of invulnerability. For example: This has always been the problem with nuclear missile defense. If you start building a ICBM defense system, you might be deluded into thinking that Russian/Chinese ICBMs can't hit you (and vice versa). Same is true here to a lesser extent.
- If the attackers added even a little bit of inexepensive control technology to their rockets, these missiles would all be landing on populated territory (if they were really smart, ala global guerrillas, they would be targeting infrastructure and not populations). A miss rate of ~20% would yield significant damage given the accuracy of the trajectories.
- Drones. Here's where it become interesting. Low cost drones flying at very low levels combine extremely high accuracy and extremely difficult targets. They are, in effect, a poor man's cruise missile. In the 80's, the USSR found that the costs of an air defense system required to defend against US cruise missiles was completely beyond their means. While this is on a much smaller scale, it still radically expands the costs.