The Pentagon last week rolled out its Nuclear Posture Review, which lays out in broad terms America’s strategy of deterrence by maintaining a powerful arsenal of nuclear-armed submarines, bombers, and land-based intercontinental ballistic missiles.
The unclassified version of the document is intended to send a clear message to friend and foe alike that any nuclear or devastating conventional attack against the U.S., or allies who come under America’s nuclear umbrella, will be met with a response that will exceed any military or political advantage.
Critics say the Trump policy lowers the threshold for the use of nuclear weapons and therefore raises the risk of nuclear war. The Pentagon insists the opposite is true. Here’s a quick guide to the 75-page document, which will guide nuclear policy under President Trump.
What is the goal of the NPR? The goal, first and foremost, is to prevent nuclear war by deterring potential adversaries from even thinking about attacking the U.S. and thereby risk nuclear annihilation. Second is to reassure U.S. allies that America has their back, so they have no need to acquire nuclear weapons of their own. And third is to maintain enough nukes to be a credible deterrent, while not having so many that it provokes a political backlash in Congress. The idea is to err on the side of more, because if deterrence fails, the result can be war, the worst of all outcomes.
How many nukes does the U.S. want? The Trump policy, like all the previous strategies, endorses the concept of the triad. The U.S. believes a credible deterrent consists of 400 land-based ICBMs in silos spread across five western states, 240 submarine-launched missiles on subs hiding deep under the ocean around the world, and 60 bombers with gravity bombs and air-launched cruise missiles. The U.S. is already embarked on a 30-year, $1.2 trillion program to modernize all three legs of the triad, with new submarines, long-range stealth bombers, and ICBMs to replace the Cold War era arsenal that is reaching the end of its useful life.
What about all the talk about new low-yield weapons? While the nuclear-tipped Trident D-5 missiles on a single ballistic missile submarine would be enough to end life on the planet as we know it, it’s not much of a deterrent to Russia, which has been busy building a whole new line of tactical low-yield weapons as part of its doctrine of “escalating to deescalate.” Over the past two decades, Russia has been amassing a stockpile of more than 2,000 so-called “non-strategic” weapons, including air-to-surface missiles, gravity bombs, depth charges, short-range ballistic missiles, ground-, air-, and sea-launched cruise missiles, anti-aircraft missiles, torpedoes, and an underwater nuclear drone. The Russians have more low-yield weapons than they have high-yield strategic weapons.
So wait, this is all about the Russians? Exactly. At least to extent that the Trump NPR differs from the Obama NPR drafted in 2010, before Russia seized Crimea and invaded eastern Ukraine. The Pentagon says that with his vast arsenal of low-yield weapons, Russian President Vladimir Putin believes he can threaten a limited nuclear strike, and the West will be paralyzed because the U.S. has no credible option to respond. The U.S. does have a low-yield gravity bomb, the newly-modernized B-61, but for a U.S. bomber to deliver, it would require penetrating Russia’s robust air defense.
So, what kind of low-yield weapons does the U.S. want to add to its arsenal? The Pentagon has two plans, a quick fix and a longer-term plan. The quick fix is to take the W-76 warhead on submarine-based Trident missiles and convert a small number of them to low-yield weapons. That can be done fairly quickly and easily because the warhead is already undergoing modernization. It has two parts: a massive fusion bomb that is triggered by a much smaller fission device. Remove the fusion bomb, and presto, you have a much smaller nuke. The second plan is to develop a whole new submarine or ship-launched cruise missile with a low-yield warhead. But that’s years away, and could be negotiated away if the Russians ever get serious about reducing the number of smaller nukes that are not covered by the New Strategic Arms Reduction Treaty, which currently limits each side to 1,550 strategic weapons.
Won’t low-yield weapons lower the threshold for nuclear war? Only if the U.S. intends to go to war, which it insists it does not. The Pentagon says the idea is not to lower the U.S. threshold for using nuclear weapons but rather to raise the Russian threshold by preventing Putin from making the mistake of thinking the U.S. has no good options if he were to use or threaten to use mini-nukes to intimidate NATO. “In no way does this approach lower the nuclear threshold,” writes Defense Secretary Jim Mattis in a preface to the NPR. “Rather by convincing adversaries that even a limited use of nuclear weapons will be more costly than they can tolerate, it in fact raises that threshold.”
Then, why are arms control advocates alarmed? They believe that nuclear weapons that can be used with limited effects will be more tempting to a president facing a crisis. And they think that the Trump policy expands the non-nuclear scenarios under which the U.S. might contemplate a nuclear response, such as a massive cyber attack. But the Pentagon says the language in the new NPR is identical to the 2010 Obama-era document when it comes to a U.S. nuclear response to a non-nuclear attack. “The United States would only consider the employment of nuclear weapons in extreme circumstances to defend the vital interests of the United States, its allies, and partners,” the NPR states. It further defines those “extreme circumstances” to include “significant non-nuclear strategic attacks.” For example, attacks on major civilian population centers, or a conventional strike on a nuclear command center, or an attack against early warning satellites. Asked for an example of the kind of non-nuclear attack that might provoke a U.S. nuclear response, one official said a North Korean missile, topped with deadly anthrax, and fired at an American city might do it.
Doesn’t the U.S. have more than enough nukes to deter any rational adversary? Funny thing about deterrence, it’s all in the mind of the adversary. What the U.S. thinks will deter the Russians doesn’t matter. It’s what they think. And the U.S. has collected a large body of evidence saying that the Russians think their strategy to escalate to intimidate adversaries has some prospect of working. So the strategy the U.S. uses to deter North Korea, by saying “if you attack us we will end your regime,” doesn’t really work with Russia. The message the Pentagon has for Russia is that any nuclear first use, however limited, “will fail to achieve its objectives, will fundamentally alter the nature of the conflict, and will trigger incalculable and intolerable costs for Moscow.”
