Could a North Korea ICBM attack on the US breach anti-missile defences?

Hours before a meeting of the leaders of South Korea and Japan in Tokyo today (Thurs), North Korea launched a 70-minute test flight of an intercontinental ballistic missile (ICBM). Timed to provoke tensions as the two leaders met, the missile, capable of reaching the United States, flew for about 1,000 kilometres (620 miles) and fell into the sea between the Korean peninsula and Japan. Last month, rumbling through Pyongyang’s Sung Square under the watchful eye of North Korean leader Kim Jong-Un, eleven monster Hwasong-17 ICBMs raised the first doubts about America’s ability to withstand a nuclear strike by North Korea. Each Hwasong-17 is potentially capable of carrying multiple warheads, posing a huge challenge to the 44 anti-ballistic missile (ABM) interceptors, strung out in long lines of silos across bases in Alaska and California, expecting to respond to a “limited” ICBM strike by either North Korea or Iran. Unlike Donald Trump, who adopted an ultimately abortive “let’s be friends” policy with Kim, President Biden has shown little interest in pursuing a similar charm offensive with Pyongyang. However, the White House and the State Department have attempted on numerous occasions to restart talks on almost anything to ensure some form of communication with North Korea. All to no avail. That leaves the missile defences installed at Alaska’s Fort Greely and California’s Vandenberg as America’s last line of defence. In contrast to Ronald Reagan’s vision of a Star Wars space-based missile defence shielding the US and Europe from a mass Soviet nuclear strike, the interceptors were all about North Korea and Iran. Washington has stressed to a sceptical Russia and China that they are purely for combating a small-scale threat, not to undermine the nuclear deterrent of their superpower rivals. Moscow never trusted the US on this, but the fact that a mere 44 interceptors were installed should have convinced even doubting Russian generals that the American ABM system was not aimed in their direction. However, that reassuringly small number’s ability to handle a limited strike from North Korea is now in question. Some non-government nuclear missile experts in the US have suggested America’s missile interceptors could be overwhelmed by a mass attack from North Korea’s 11 Hwasong-17s. One was quoted as saying that the US interceptor had only been test-flown once at night and had failed. This proved, the expert said, that the system could not operate effectively in the dark and needed the sun to make it easier to track an enemy reentry vehicle carrying a nuclear warhead. The reality is more complex, although it is true that the American interceptors, each with only one kill vehicle on board, would theoretically be outnumbered if North Korea managed to get all 11 Hwasong-17 missiles to work and each of the multiple warheads performed as intended. This is far from guaranteed - some of the 11 on display in the streets of Pyongyang might even have been dummies. Missile defence is not just about intercepting incoming warheads. In terms of US strategic planning, there would be a far more holistic approach to a nuclear threat from North Korea, involving intelligence-gathering, warnings to Pyongyang and if necessary, preemptive action. “In a war scenario between North Korea and America, the US is not going to be waiting for Pyongyang to launch missiles before reacting, “said Ian Williams, deputy director of the missile defence project at the Washington-based Centre for Strategic and International Studies. “The reality is that as soon as there is notification of an imminent launch of nuclear missiles, the US would go after them, destroying them before launch,” he said. “There’s missile defence and there’s missile defeat. The US would use many methods to neutralise their missiles, including hypersonic missiles that are being developed to reach their target in a very short timescale,” Williams said. “Then there are electro-magnetic weapons that can disable their launch mechanisms and we would target their command centres to disrupt missile-launch orders. So it’s not just about how many interceptors we have got to take out their missiles. It’s about an overall homeland defence strategy,” he said. Nevertheless, the Pentagon, aware of North Korea’s increasing missile capabilities, has contracted Northrop Grumman to develop the next-generation interceptor for what is called the ground-based mid-course defence system. Each of the new interceptors will have multiple kill vehicles. This will change the dynamics of any future confrontation with North Korea, although the first test of this new system is not likely until 2026. The current interceptors have suffered from failed tests in the past, 40-50 per cent. But none of the tests have resulted from systemic technical faults . There were on-board battery problems with one interceptor and in a single instance, corrosion on the silo arm prevented an interceptor from launching. The tests go back to the prototype era of 1997 when initial failures would have been expected. The fact that there hasn’t been a test for a year or two might be a cause for concern. Interceptors that sit all day and night in silos should be flight-tested more regularly. But the military seem confident that the 40 deployed in three silo fields in Alaska and the four in one silo field in California are ready for action. The current defence budget allows for 20 more interceptor silos to be installed at Fort Greely. Work is underway. There have also been longstanding discussions about building another missile defence site in the east of the country and choices have been narrowed down to Maine, Ohio or New York state. But no money has yet been allocated in the budget. The interceptors are hit-to-kill weapons. There is no explosive charge in the kill vehicles. They have to find the incoming nuclear reentry vehicle from amongst the mass of flying junk created when the warhead separates from the rocket and booster systems, and hone in on the target. When the new interceptor with multiple kill vehicles becomes operational, each one will be capable of taking on several targets at once. But there will still be a set radius of action for every interceptor. In missile terminology they call the target being “in the basket.” Claims that the current interceptor can’t function at night are dismissed. The electro-optical computer technology fitted to the hit-to-kill system is similar in sophistication to the James Webb space telescope. “There is always enough ambient light off the moon, so there is no problem operating at night,“ Williams said.