How Capable Are Japanese Patriot Missiles Against Threats?

Last Line Of Defense

Ever since North Korea’s nuclear program and the development of ballistic missiles were exposed, Japan has been eager to create a Missile Defense system to intercept such threats.

This thirty-year effort has paid off, with the establishment of a two-layer defense:

(1) First attempt by Aegis destroyers at sea
(2) Final interception by land-based Patriot Missiles (PAC-3)

As such, the PAC-3 missiles are regarded as literally the last line of defense for Japan, leading to its procurement of more than 48 units.

• General Overview (PAC-3 MSE)

Developed by the US for air defense, the Patriot proved its usefulness in intercepting ballistic missiles during the 1991 Gulf War, and were later viewed by the Japanese government as a critical asset for countering the North Korean missile threat.

Though the Patriots were originally designed for anti-aircraft purposes, the PAC-3s introduced by Japan in 2006 were modified versions capable of destroying ballistic projectiles.

The PAC-3 was placed under the Air-Force (JASDF) rather than the Army, mostly because of JASDF’s historic role in handling airborne threats.

Each unit includes a launcher, multi-function radar, fire-control system, information processing device and a power supply equipment, all of which can be loaded on trucks for rapid deployment.

After deployment, the system can be remotely operated by a minimum of three people, and is able to perform independently in case communications with air defense command are severed.

The multi-function radar

In the event of actual combat, the unit will fire two PAC-3 missiles towards each target to ensure its certain kill.

Considering the fact that PAC-3s only have a range of 30km/18.6miles, the reaction time against warheads plunging at a speed of several miles per second is limited to less than a minute. So, this double insurance is actually rational to guarantee its effectiveness as the last line of defense.

Upon firing, the missiles are guided by the multi-function radar, later switching to its own active radar to seek and track targets.

Following final adjustments by small motor injections, the PAC-3 is to destroy its airborne target, but while the conventional version “the CRI (Cost Reduction Initiative)” directly collides with the enemy warhead, the newer “MSE (Missile Segment Enhancement)” uses a fragmentation method.

Not Enough PAC-3s?

Currently, JASDF operates a total of 48 launchers allocated to 24 air defense units across the country.

While this may seem like a lot, it is unfortunately not enough to cover the entire territory of Japan due to the PAC-3’s protection range being a diameter of 50km or 31miles (though the story differs when Aegis destroyers are deployed at sea).

Nonetheless, since the PAC-3s are mobile units, they are able to deploy rather swiftly via the vast network of highways and national roads. For instance, emergency deployments were conducted to rural areas of Shimane and Ehime Prefecture following the danger of falling debris from North Korean missile tests.

Moreover, the PAC-3s operated by JASDF have been successfully replaced by the more agile and wide-range  “MSE” versions. The PAC-3 MSE is capable of coping with smaller nimble targets, thus enhancing the overall capability of JASDF air-defense units.

With the PAC-3’s mobility and the new MSE missiles in line, JASDF seems to be confident in protecting the entire territory of Japan, and the idea of forming additional PAC-3 units is absent at the moment.

100% Success Rate In Tests

So, exactly how good are Japanese PAC-3 units at intercepting targets?

JASDF has conducted several live-fire tests in the past and maintains a 100% success rate for now. These tests take place in the United States where it is possible to simulate real combat scenarios and easier to evaluate performance.

Because it is done at the same facilities, under similar scenarios, it is fair to say the capability of JASDF PAC-3 units are equivalent to that of its US counterparts.

Perhaps one interesting factor behind the success rate is the scarce opportunities to fire live rounds. Owing to budget constraints and ammunition shortage, Japan’s Self Defense Forces do not have the luxury of firing abundant rounds for training.

In a ironic twist, this compels SDF personnel to demonstrate their potential with little experience of live-fire training, paving way for a unique spirit in hitting the target with a single shot.

In any case, the JASDF PAC-3 units have proven themselves capable of intercepting simulated ballistic targets, but other factors will definitely disrupt such performance in actual combat.  After all, simulations are just simulations.

But, as destroying airborne ballistic missiles remains an extremely difficult task, something not any nation can just achieve even in simulated tests, the abilities demonstrated by JASDF is the best we can hope for in this peacetime.