A successful U.S. test strike against an intermediate-range missile Wednesday raises fresh questions about the feasibility of the U.S. military intercepting a North Korean missile test as a means of deterring the country from future provocative launches.
But experts say it may not be a practical option since most North Korea missile tests have been aimed at the open seas, including a North Korean missile launched to fly over Japan on Tuesday. The missile defense systems are designed to defend U.S. territory or that of an ally from incoming missiles.
"We don’t have the capability to shoot down every missile every time one is launched,” said David Maxwell, associate director of Georgetown University’s Center for Security Studies. “We have no need to defend the Pacific Ocean."
Even the missile that crossed Japan, the first such launch, may have been difficult to intercept. It flew nearly 1,700 miles and reached an altitude of 340 miles.
The “lofty” trajectories of some of the recent North Korean launches may complicate efforts to intercept the missiles, said Ian Williams, an analyst at the Center for Strategic and International Studies.
The high trajectories are useful for North Korea to test the range of its missiles without striking foreign territory, but a missile aimed at a real target would fly on a flatter flight path.
U.S. and allied radar systems can quickly determine where a missile is headed and whether it poses a threat to populated areas. The systems can track test launches also, but there may not be interceptors in a position to shoot them down if they are headed for the open seas.
“Ballistic missiles are easy (for radar) to see,” Williams said. U.S. radar systems are very effective at quickly determining where a missile will land based on its speed, direction and other information, he added.
Still, some analysts say intercepting a North Korean missile test, if the circumstances allow it, could be an effective military response to North Korea, which has consistently defied international sanctions designed to prompt it to abandon its nuclear weapons program.
“It may be that this is a natural next step, to do something different,” said Thomas Karako, another analyst at the Center for Strategic and International Studies.
Tensions between the United States and North Korea have been building in recent weeks.
“The U.S. has been talking to North Korea, and paying them extortion money, for 25 years,” Trump tweeted Wednesday. “Talking is not the answer!”
North Korea showed no sign of backing down. The official Korean Central News Agency reported Wednesday that the Hwasong-12, the first missile the nation has fired over Japan, was “guided” by leader Kim Jong Un and observed by senior officials.
It said the launch of the intermediate-range rocket was “part of the muscle-flexing” in reaction to ongoing military drills by the U.S. and South Korea, “in disregard” for the North Korean regime's “meaningful and crucial warning.”
Defense Secretary Jim Mattis met with South Korea's Defense Minister Song Young-moo Wednesday. “There is already very strong collaboration, we always look for more," Mattis said before the meeting.
The Missile Defense Agency said Wednesday it had conducted a successful missile defense test that intercepted a medium-range ballistic missile off the coast of Hawaii.
The USS John Paul Jones detected and tracked a missile launched from the Pacific Missile Range Facility on Kauai with its onboard radar, before intercepting it with SM-6 missiles, the agency said.
The key components of America’s missile defense arsenal include ground based interceptors designed to defend the United States, ship-based Aegis interceptors and the THAAD or Terminal High Altitude Air Defense System.
The THAAD system intercepts missiles as they re-enter the atmosphere. The Aegis system is designed to intercept missiles that are "mid-course" or outside the earth's atmosphere.
The United States has deployed the THAAD system in South Korea and has Aegis-equipped ships in the region. Japan’s self-defense forces also have ships equipped with Aegis radar systems.