Thursday, October 13, 2005

Advantage Moving To Defense

Historically, the advantage in warfare has swung between attack and defense. Currently attack has the advantage - the missile always gets through. That's in the process of changing, as shown by the Israeli deployment of laser defenses. If this works, the world will change profoundly.

In WW1, the German forces charged into Belgium and France expecting a repeat of their quick 1871 victory in the Franco-Prussian war, only to be stopped by the defensive power of the machine gun and artillery. Then, 4 years later, the newly-invented Brits tanks charged through previously impregnable German trenches and set the scene for the offensive tank battles of WW2.

Since 1918, offense has had the advantage, with only a few exceptions as new technologies appeared - radar in the Battle of Britain. Most recently, the missile has been dominant - from the lowly RPG up to the
MIRVed ICBM, missiles have been too fast and nimble to stop.

But now faster sensors, computers and defensive weapons have appeared.
Earlier posts noted the rapid improvement of the Aegis ship-borne missile system that destroys incoming IRBMs and ICBMs by directly hitting them after their boost-phase.

An even more interesting technology is the high-energy laser. Integrated with a high-resolution radar and controlled by advanced battle management software, this acts a a bit like my lizards. The laser slews to face the target in a fraction of a second and (fortunately unlike my lizards) destroys them with a beam that propagates at the speed of light.

Speed of propagation is important, since an incoming missile will perform evasive maneuvers once it detects a defensive radar has locked on - the laser doesn't give it time to fire its thrusters.

The counter to this is to use mass launches that overwhelm the radar's tracking capacity, battle manager and laser recharge time, but after a lot of work, this is largely
solved (my ellipsis):

The IDF has deployed a sophisticated new radar system near the Gaza Strip, which it is hoped will give early warning to Israeli residents of incoming Katyusha missiles, Kassam rockets and possibly mortar rounds, military sources have told The Jerusalem Post.


The system is the prototype for a state-of-the-art wider missile defense system, the (Tactical High-Energy Laser - THEL), which has been in joint development by Israel and the United States for almost a decade and is ultimately intended to be able to intercept such incoming fire with a high-energy laser beam.

Image from Northrop Grumman.

The weapon has decent test results:

During a recent test conducted on Aug. 24, 2004 the system shot down multiple mortar rounds, demonstrating potential its battlefield application for to protection against common threats. The test represented actual mortar threat scenarios. Targets were intercepted by the THEL testbed and destroyed; both single mortar rounds and salvo were tested.

I suspect that the promise of this system is part of the rationale for the Israeli isolation strategy - building their fence and withdrawing from Gaza.

There are still problems - THEL needs 5 seconds to recharge between shots. Plus the enemy will switch his launch points away from fixed THEL kill sphere, so unless the Israelis can afford to build them all around their borders (including their coast), they need better mobility.

I'd expect them to overcome these problems quite quickly. But until they know exactly how and when they can field these defenses, I wouldn't expect them to give up further territory that they might later need for radar and THEL sites.

A move to defensive advantage will take 5 to 10 years to play out, and the defenses will be restricted to First World high technology nations for decades, leaving those nations free to divert their resources to other things. Such as settling Mars, or collapsing into decadence.