As I have been writing about in recent weeks, the United States and its Asia-Pacific allies have been scrambling to respond to the rapid advances in North Korea’s nuclear program. One idea that has been floated is to redeploy tactical nuclear weapons in South Korea and perhaps even Japan.
To be sure, there have long been lawmakers in South Korea who have been advocating this idea. And, although South Korea’s government continues to oppose such a measure, the idea is been discussed at the highest levels. For instance, South Korean Defense Minister Song Young-moo said that he mentioned to his American counterpart, James Mattis, “that some South Korean lawmakers and media are strongly pushing for [U.S.] tactical nuclear weapons” to be returned to South Korea.
Then, NBC News reported that the Trump administration is “not ruling out” redeploying the tactical nuclear weapons to South Korea. A few days later, Sen. John McCain also argued that the United States should “seriously consider” putting nuclear weapons back in South Korea, and a senior delegation of South Korean lawmakers was in Washington this week to ask for them. Not to be outdone, former Japanese Defense Minister Shigeru Ishiba called for his country to start discussing hosting U.S. nuclear weapons, despite Tokyo’s long-standing pledge that it will not possess, manufacture or host nuclear weapons on Japanese territory. This is particularly notable given that Ishiba has been bandied about as a possible successor to Japan’s current prime minister, Shinzo Abe.
I have argued repeatedly that the United States should use the North Korean threat to strengthen its military posture in the Asia-Pacific region. Nonetheless, deploying nuclear weapons in South Korea or Japan is a terrible idea and not for the usual reasons given (Kim Jong-un is not going to surrender his nuclear weapons because America decided not to redeploy tactical nuclear weapons to the Korean Peninsula). Instead, there are at least four major reasons why America should not send nuclear weapons to Asia.
An Idea Past Its Expiration Date
The United States began forward deploying tactical nuclear weapons in Asia and Europe in the 1950 for one simple reason: it had no other choice. The initial Cold War nuclear-capable bombers like the B-29 and the B-50 did not have the range to conduct a round-trip flight from the United States to the Soviet Union (or North Korea). The United States also lacked a missile with sufficient range at this time as well—the first intercontinental ballistic missile wasn’t declared operational until 1959.
Still, the initial ICBMs and the long-range bomber, the B-52, were not able to meet America’s military needs at the time. During the Cold War, the United States intended to use tactical nuclear weapons to defeat conventional attacks by the Soviet Union in Europe and North Korea on the Korean Peninsula. The bombers flying from the United States took far too long to get to the fight. While U.S.-based ICBMs could reach the peninsula quickly, they were widely inaccurate and therefore ill-suited to be used against tactical targets. Especially starting in the 1980s and improving since, America’s long-range nuclear-capable missiles, both the land-based and sea-based ones, are extremely accurate, so they perform the same missions envisioned for tactical nuclear weapons.
Relatedly, basing tactical nuclear weapons in Japan or South Korea would have absolutely no military utility. This is especially true in the case of Japan. Since America’s missiles are regulated by the Intermediate Range Treaty (INF), it can’t produce non-ICBM ground-based missiles with a range of over 500 km. This is not far enough to reach North Korea from Japan. A ballistic missile with a less than 500 km could reach North Korea from the Republic of Korea. However, to hit the northern part of the Democratic People’s Republic of Korea these missiles would have to be based in northern part of South Korea, which would make it especially vulnerable (more on this below).
More to the point, as alluded to above, the incredible accuracy of precision-guided missiles using nuclear weapons militarily unnecessary under most circumstances. If you can hit a target straight on the mark, you don’t need a high yield bomb to destroy it. But, the United States does have increasingly higher-yield conventional bombs just in case (albeit ones delivered by air).
But most importantly, the United States and South Korea do not need to use tactical nuclear weapons to defeat a North Korean invasion. The alliance’s conventional capabilities are more than adequate for this task. The only real mission nuclear weapons serve on the Korean Peninsula is deterring North Korea from using its own nuclear weapons, and retaliating if it does attack America or its allies with the bomb. American ICBMs, bombers and ballistic missile submarines would be the preferred systems for carrying out this retaliation. As Secretary of Defense Mattis put it this week , “We have a nuclear deterrent and its location is immaterial.”