The Cold War was waged and won in many places, including this beach city, home to the Rand Corp. Created in 1948 to think about research and development as it effects military planning and procurement, Rand pioneered strategic thinking about nuclear weapons in the context of the U.S.-Soviet competition. Seven decades later, it is thinking about the nuclear threat from a nation created in 1948.

When Defense Secretary Jim Mattis said that any North Korean use of nuclear weapons would draw an “effective and overwhelming” U.S. response, he did not, according to Rand’s Bruce W. Bennett, “overcommit” the president by saying that the response would be nuclear. But an overwhelming response could be.

On Jan. 1, North Korea’s 33-year-old leader, Kim Jong Un, said that his regime was at “the final stage in preparations to test-launch” an intercontinental ballistic missile, perhaps one capable of reaching the United States’ West Coast. On Jan. 2, Donald Trump tweeted: “It won’t happen!” He thereby drew a red line comparable to his predecessor’s concerning Syrian chemical weapons. So Trump, who excoriated Barack Obama for ignoring that red line, must, Bennett believes, be prepared to threaten actions that would prevent North Korea from learning from its test, actions such as shooting down the missile.

The United States has 30-some ground-based interceptor missiles at Fort Greely in Alaska and others at Vandenberg Air Force Base in California. This small capability is intended to cope with an accidental firing by an adversary, or an intentional firing by a rogue general, or to deter or defeat a deliberate attack by an adversary with a small nuclear arsenal, such as North Korea. Will the U.S. anti-ballistic-missile system work? Bennett says technologies can go wrong, so this would be an opportunity to fix any failures. And unless we then are prepared to shoot down theater-range ballistic missiles, we will signal less-than-convincing commitment to South Korea and Japan. To those who say it is premature to conclude that Kim is capable of delivering a nuclear warhead, Bennett says: In 1966, China, in its fourth nuclear test, just two years after its first, had a missile carry a nuclear weapon to its detonation over its western desert.

(Video: Reuters / Photo: AFP)

In 2006, William Perry, who had been defense secretary for Bill Clinton, and Ashton Carter, who would be Obama’s final defense secretary, recommended U.S. action to destroy any ICBM set for testing on a North Korean launch pad. But that nation’s conventional retaliatory capabilities, including artillery and rockets capable of inflicting considerable damage on at least Seoul’s northern suburbs, forestalled this. And North Korea has perhaps 1,000 tactical-range ballistic missiles capable of striking throughout South Korea and Japan. Furthermore, North Korea has cyberwar, commando and sabotage capabilities.

Today, U.S. surface ships and submarines alone could deliver dozens of cruise missiles, and each of up to 10 B-2 bombers could carry two Massive Ordnance Penetrators to destroy underground leadership or missile bunkers. But as soon as Kim has one or more ICBMs (probably road-mobile) capable of delivering, on short notice, a nuclear payload to, say, Santa Monica, preemptive U.S. action, even just against his nuclear infrastructure, might be too risky.

Furthermore, preparations for a more ambitious strike — against North Korean artillery and rockets, ports, airfields, command-and-control centers, leadership bunkers and forward-positioned forces — might be apparent and might provoke Kim to strike first against Seoul and U.S. forces in South Korea. South Korea talks openly of creating, this year, a “decapitation brigade” involving perhaps as many as 2,000 troops whose mission would be to eliminate North Korea’s leadership in the event of war.

Kim recently dismissed the head of his secret police, the latest sign of insecurity. Bennett believes Kim, undeterred by tweets, might test his ICBM for internal purposes — to impress restive North Korean elites. Bennett suggests that the threat to shoot down the test flight would constructively exacerbate Kim’s problems. As might U.S. propaganda, for example by reminding North Korean elites that China’s president has had eight summits with South Korea’s president in the past four years but never has had one with Kim, whom China apparently considers not important.

North Korea, which has been run opaquely for the Kim family’s benefit since 1953, is approaching a red line. Although the line was drawn before Trump took office, perhaps it represents continuity. It prefigured the kind of improvisational governance that has made his early weeks so interesting.

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