The U.S. Navy will try for the first time to shoot down an intercontinental ballistic missile in the middle phase of the ICBM's flight, the Pentagon announced on Jan. 17, 2019.
But it's not clear the Navy's SM-3 missile is up to the task. Even if it is, its deployment could lead to a dangerous arms race.
The SM-3 announcement was part of the Trump's administration's roll-out of its new Missile Defense Review.
"Our goal is simple," Pres. Donald Trump said. "To ensure that we can detect and destroy any missile launched against the United States, anywhere, any time and any place."
That includes hitting ICBMs during the midcourse phase of flight. At present just one weapon, the U.S. Army's Ground-Based Midcourse Defense rocket system, in theory can strike an ICBM.
A new version of the Navy's own SM-3 -- its main missile-interceptor -- could reinforce the GMD. "The SM-3 Blk IIA interceptor is intended as part of the regional missile defense architecture, but also has the potential to provide an important 'underlay' to existing [ground-based interceptors] for added protection against ICBM threats to the U.S homeland," the missile-defense review states.
The Army operates 44 GMD rockets at based in Alaska and California. The Pentagon said it would request funding for 20 more GMD missiles.
The Navy bought 90 older SM-3 Block IB missiles in 2017 and 2018. The Missile Defense Agency announced it would test the SM-3 Block IIA against an ICBM-class target in 2020 as part of a $230-million development effort.
As of late 2018 the U.S. fleet included 38 Aegis-radar-equipped destroyers and cruisers that are compatible with the missile-defense versions of the SM-3. The Navy wants to grow the BDM fleet to 41 vessels in 2019.
"The combination of increased ship numbers and capability will result in a more flexible and resilient Aegis force with significantly greater missile defense capability," the review notes.
The U.S. military's two ground-based Aegis Ashore systems in Romania and Poland also fire SM-3 interceptors. These, too, are due to receive the latest version of the SM-3.
During the midcourse phase of flight, an ICBM travels above the atmosphere at 20 times the speed of sound. The idea that an SM-3 could hit such a high and fast target is predicated on the GMD's supposedly proven ability to do the same.
In a dramatic test on May 30, 2017, the Missile Defense Agency fired a GMD rocket and struck a target missile 60 miles over the Pacific Ocean. The target was in the same class as an ICBM, the military stated.
"Although this was a developmental test, this is exactly the scenario we would expect to occur during an actual operational engagement," Navy admiral James Syring, head of the Missile Defense Agency, told reporters.
The test was the first time any U.S. missile-defense system had intercepted an ICBM. All previous missile-defense tests targeted much slower and lower-flying missiles.
But the May 2017 test might not have been as realistic as the Pentagon claimed it was. Laura Grego, a missile expert with the Union of Concerned Scientists based in Massachusetts, examined the distances the two test rockets were expected to travel—and how quickly—and, the day before the test, concluded that the target rocket would probably be significantly slower than an ICBM launched from North Korea would be.
A North Korean ICBM targeting Los Angeles would likely reach a velocity of 6.7 kilometers per second. The target in the 2017 test probably maxed out at 5.9 kilometers per second, if not slower, Grego claimed.
If the GMD cannot in fact intercept an ICBM, the SM-3 likewise might suffer the same limitation. The key, for impartial observers of the planned 2020 test, will be the speed and altitude of the target rocket. If the target flies lower and slower than a real ICBM would do, then the test would be inconclusive for the purpose of developing a working missile-defense system.
Even if it works, the SM-3 could prove provocative, warned Hans Kristensen and Matt Korda, both missile experts with the Federation of American Scientists in Washington, D.C.
Kristensen and Korda explained that they are worried that the SM-3 test could encourage Russia and China to develop new strategic weapons to defeat the interceptor, potentially spurring a dangerous nuclear arms race.
"It is notable that the decision to conduct such a test seems to hinge upon technological capacity and not the changes to the security environment," Kristensen and Korda wrote.
In other words, the Trump administration is pushing for new defenses against ICBMs while traditional deterrence still is working just fine.
Russia apparently isn't waiting to see if the SM-3 actually can hit an ICBM. In 2018 Russian president Vladimir Putin rushed development of the Kremlin's new hypersonic Avangard nuclear missile, a Mach-20 glider that travels lower than an ICBM does, potentially foiling missiles such as the SM-3 that only work at high altitudes.
"It is very clear that Putin's strategy is to develop nuclear strike systems that even someone who is completely ignorant would understand cannot be addressed with missile defenses," explained Ted Postol, a missile expert at the Massachusetts Institute of Technology.
As a defense against ICBMs, the SM-3 might not work. And even if it does, it might only make America less safe.
David Axe serves as the new Defense Editor of the National Interest. He is the author of the graphic novels War Fix, War Is Boring and Machete Squad.