Missile countermeasures: North Korea's threat, Israel's experience

Aug. 15 (UPI) -- North Korea's nuclear weapons and ballistic missiles have been making headlines again. There's also been serious controversy over how the United States and other countries should react to that threat.

To that end, it might help to examine Israel's experience in dealing with actual rocket attacks. Some of my research has explored the properties of its interceptor systems.

Israel is a leader in missile countermeasures because of its neighbors. It has experienced rocket fire for more than a decade from Hamas militants in Gaza and Hezbollah militants in Lebanon. The country hasn't forgotten Iraq's 1991 Scud missile strikes. It also worries about future attacks from Syria and Iran.

Israel has consequently developed a set of countermeasures that provide it with a layered defence:

Blockade

One way to guard against missiles is to prevent hostile countries from getting them. Trade sanctions and military blockades can assist this.

Israel restricts trade into Gaza for this reason. However, Hamas responds by smuggling rockets inside other shipments. It also bypasses the blockade by producing Qassam rockets locally.

International sanctions against North Korea have likewise had limited success, partly due to its relationship with China. North Korea has also made domestic weapons development a national priority.

Deterrence

We can try to discourage the use of missiles by threatening to retaliate with our own weapons. But success depends on the opposing leader's goals. Some might risk or even welcome retaliation.

For example, Israel has deterred Hezbollah from firing rockets for 11 years. But Hamas has not been deterred, as it benefits politically from occasionally provoking Israel.

Deterrence is the default solution regarding North Korea, as it was during the Cold War. It may be what U.S. President Donald Trump meant by his "fire and fury" comments. If North Korea ever uses nuclear weapons, it will invite massive U.S. retaliation and likely end the regime's rule.

Pre-emptive strikes

The direct military solution to missiles is to destroy them on the ground. This counterforce approach assumes the missiles can be located and effectively attacked. It also risks collateral damage against civilians and diplomatic repercussions with other countries.

Israel conducts clandestine airstrikes against selected Hezbollah missile shipments for this reason. It destroys rockets on a larger scale during its operations against Hamas. One challenge is the large number of rockets. Israel has destroyed thousands, but thousands more remain. Another problem is rockets being stored in civilian areas like schools. Collateral damage there is unavoidable.

Donald Trump's "military options" presumably include pre-emptive strikes. There are "only" about 60 North Korean nuclear warheads. But the United States would not want to miss even one. They may be hard to locate in that highly secretive country. They also may be well-sheltered and difficult to destroy without causing heavy civilian losses.

Interception

Once missiles have launched, defenders may try to shoot them down. Such interceptions are difficult to achieve, but make spectacular videos.

Israel has developed several interceptor systems. Iron Dome intercepts short-range rockets, David's Sling handles medium-range missiles and Arrow targets long-range missiles.

Arrow claimed its first interception this year. Iron Dome has engaged hundreds of rockets since 2011, though with much debate about its effectiveness.

The U.S. also has several interceptor systems: Ground-Based Mid-Course Defense, Terminal High Altitude Area Defense, Aegis (Standard) Ballistic Missile Defense and Patriot. Patriot has limited combat experience, while the others have none. Their effectiveness against North Korean missiles is uncertain.

Even good interceptors aren't perfect. Iron Dome cannot engage every incoming rocket, and sometimes it misses those it engages. Fortunately, the rockets have small warheads. The United States would likely face only a handful of North Korean nuclear warheads. But missing even one could be devastating.

How attackers try to avoid detection

There are also ways for attackers to avoid interception. The simplest is to overload the interceptors by firing many missiles at once. Hamas has been unable to do this against Iron Dome but Hezbollah has enough launchers to try.

North Korea may have too few nuclear missiles to overload U.S. systems. But it could succeed with its numerous conventional missiles.

Attackers might also try fooling interceptors into chasing non-threatening missiles or ignoring threatening ones. The former wastes interceptors, while the latter lets missiles through. Possible methods include jamming, decoys or maneuverable warheads. This approach is probably not worthwhile for rockets fired at Israel. North Korea, however, could develop decoys to accompany its warheads.

An attacker could instead try shooting missiles at an interceptor system to destroy it. However, such counter-battery fire uses up valuable ammunition. Hamas artillery rockets are too inaccurate to make this trade-off profitable. Hezbollah could attempt it with guided missiles or armed drones. North Korea would not waste nuclear warheads against interceptor systems but might shoot conventional ones at them.

Civil defenses

Finally, a country can reduce its missile casualties by preparing civil defenses. These include warning systems, bomb shelters and emergency response units.

Israel's warning system is called Red Color. Speakers, sirens and cellphone apps alert civilians of incoming rockets. The country has built concrete shelters in locations like playgrounds and bus stops, as well as in private homes. However, there is concern that attackers might someday use poison gas warheads to bypass these shelters.

The United States could revive its civil defense program, starting in Guam and Hawaii. The priority should be the warning systems. Shelter needs depend on the warheads. Even ordinary basements or concrete buildings would help somewhat against conventional explosive warheads. More sophisticated shelters and decontamination gear would be needed against nerve gas or nuclear warheads.

Complementary layers

Israel's countermeasures act together to complement each other's strengths and weaknesses. Collectively they may have prevented thousands of casualties and millions of dollars of damage.

To achieve that, the country has spent billions, including over $3 billion of U.S. aid. That's a lot to protect a small territory containing fewer than 9 million people. The cost to defend the United States or its allies would be far larger.

Michael J. Armstrong is an associate professor of operations research at Brock University.