Last week a United States’ “hit-to-kill vehicle” intercepted and destroyed a mock intercontinental ballistic missile (ICBM) for the first time during a test. Until fifteen years ago, however, anti-ballistic missiles (ABMs) like the one just tested were banned under the Anti-Ballistic Missile Treaty signed by the United States and Soviet Union in 1972.   

The treaty limited each nation to two ABM complexes, with no more than 100 interceptors deployed at a single complex.  The treaty prohibited the development of ABMs against only long-range intercontinental and submarine-launched ballistic missiles and not against shorter-range tactical missiles.    

To understand why the two adversaries agreed to limit ABMs, curator James David posed the question: What prevented nuclear war?  

“Think back to that era. Each side had thousands of nuclear weapons targeted on each other,” David said. “What kept the peace was mutual assured destruction.”

If one country were to launch its nuclear weapons in a first strike, enough nuclear weapons would survive in the other country to cause massive destruction in a retaliatory strike. This threat of mutual assured destruction prevented either side from acting, but the use of ABMs greatly disrupted that balance.

“Both sides said, ‘That’s it,’” David said.

But the changing geopolitical landscape and the growing ballistic missile and nuclear threat from countries like North Korea and Iran put the treaty in peril. In 2002, President George W. Bush withdrew despite concerns from many that a withdrawal would lead to undermining the theory of mutually assured destruction.  That never ended up happening, David said. According to David, the United States has not and will not deploy an ABM force capable of defeating a Russian or Chinese attack.   

In a short time frame, ABM technology has improved dramatically. Early ABMs had to carry nuclear warheads to stop a missile. Now, nearly all of our ABMs carry “hit-to-kill” vehicles which have to physically hit a target to destroy it.  After it separates from the booster, the “hit-to-kill” vehicle’s infrared seeker acquires and tracks the enemy missile. 

Despite the success of the recent test, David said there are still many challenges associated with anti-ballistic missile technology. “You have a target moving up to 15,000 miles per hour and you have to destroy it by physical impact,” he said. “It’s a huge, huge challenge and the tests are not always successful.”

Today, the US has four different types of ABMs deployed with each serving a specific purpose. The “hit-to-kill vehicle” recently tested is carried on the Ground-Based Interceptor, the only ABM designed to intercept an ICBM. The three other systems are designed to defend against short- and medium-range ballistic missiles—one is sea based while the others are ground based.

In 2005, the Museum collected two early versions of “hit-to-kill” vehicles, along with other artifacts that represent the growth of this technology. The Exoatmospheric Kill Vehicle (EKV) was carried in the nose of the Ground-Based Interceptor.  The Lightweight Exoatmospheric Projectile was eventually incorporated into the SM-3 ABM.    

David hopes to collect additional hardware or models that represent this growing technology. As the most recent test proves, along with their use in the Gulf War and Operation Iraqi Freedom, anti-ballistic missiles will continue to be an important component of the country’s arsenal.