The Nuclear Sponge Sucks – or, Why Do We Still Have ICBMs?

The Triad

The United States nuclear forces are often described as being a Triad of Air, Sea, and Land weapons. This refers to how the weapons are based and delivered: gravity bombs (and cruise missiles) carried in bombers; ballistic missiles (and cruise missiles) in submarines; and ballistic missiles (called ICBMs, or InterContinental Ballistic Missiles) housed in silos in the upper Midwest of the country. (This classification doesn’t include weapons with shorter range, often called “tactical” nukes; we discuss this type of nuclear weapon here on our site.) The Defense Department has long argued that these three “legs” of the triad are required for deterrence, that each “leg” serves as a hedge against failure in the others. The basic idea behind nuclear deterrence is that our nuclear weapons will deter another country from attacking us with their nuclear weapons because they realize that we would respond with a devastating retaliatory strike. (Their initial attack would be a first strike; our retaliation a second strike.)  During most of the Cold War, it was widely believed that the biggest threat was a “bolt out of the blue” surprise attack; both sides developed large land-based arsenals to prevent this. ICBMs from this era carried huge warheads, some as great at 10 megatons, and some even carried multiple warheads per missile. They were difficult to target because they were housed in “hardened” silos. Advances in technology like GPS allowed these missiles to be precisely targeted to take out a wide variety of enemy targets.

ICBMs promote instability

But those advances had an unexpected side effect: by the end of the Cold War, guidance systems had become so precise that ICBMs on both sides were now vulnerable to being destroyed in their silos. And this created a dangerous source of instability: because our enemies know the precise location of all our silos, they might be tempted to launch a first strike to destroy all the ICBMs before we could deploy them. The response of both sides to this instability was to develop a “launch on warning” strategy: as soon as incoming missiles were detected, the ICBMs would be launched so they wouldn’t be destroyed in their silos. Today, both sides still maintain this posture, which would give a president on the order of 10 minutes upon receiving notice of an attack to decide to launch, a nightmare scenario we discuss in Episode 2 of At The Brink. But the scenario ignores a fundamental problem: false alarms. No system and no person is perfect; false alarms have already happened several times on both sides (listen to Episode 1 of At The Brink). Missiles cannot be recalled; once launched, World War III has started. As Daryl G. Kimball, Executive Director of the Arms Control Association has written, “Each country’s deadly ICBM force perversely justifies the existence of the other’s, perpetuating the risk of a massive nuclear exchange that might be triggered by a false alarm or a future cyberattack on nuclear command-and-control systems.”

Are ICBMs necessary for deterrence?

Does the vulnerability of ICBMs mean that nuclear deterrence no longer works? Remember, the key to deterrence is the ability to retaliate…it’s the credible ability to launch a second strike. The Pentagon’s answer to this is to launch on warning—they would consider this launch to be the second strike. But once such an attack happens, deterrence would have already failed, and all that would be accomplished by launching the ICBMs would be to widen the inevitable destruction. But we already have a clear solution in place: the other two legs of the triad, bombers, and submarines. Our strategic bombers are in bases around the world, can take off on a moment’s notice, and importantly, can be recalled if necessary. At any given time, the majority of our ballistic missile submarines (SSBNs) are at sea. Modern sub technology makes them essentially undetectable, and this is expected to remain the case indefinitely. This means, that, unlike our land-based ICBMs, our subs and bombers are “survivable”, meaning that it would be virtually impossible to destroy them in a surprise attack. And the nuclear power they represent is stunning. For example, each sub carries 24 highly accurate Trident II ballistic missiles, each typically fitted with four warheads of yields up to 475 kilotons. Even just a single sub carries enough retaliatory power to utterly devastate any country.

The birth of the nuclear sponge

So, because we already have a robust second-strike capability, why do we need to keep our ICBMs, especially given the fact that they actually increase instability? This is where the idea of the “nuclear sponge” arose. As ICBMs became increasingly vulnerable, rather than discard them in favor of subs and bombers, the Pentagon kept them, but they gradually evolved a new mission: as a “sponge” to deplete an enemy’s nuclear arsenal. Even if never launched, they would serve the purpose of absorbing hundreds of nuclear missiles from Russia as a “missile sink” or “nuclear sponge.” This plan has long been criticized by many as “madness”, but it still remains official US strategy. In 2017, Secretary of Defense Mattis defended it; although not using the term “sponge”, he said about our ICBMs “…any enemy that wants to take us on is going to have to commit two, three, four weapons to make sure they take each one out. In other words, the ICBM force provides a cost-imposing strategy on an adversary.” As recently as 2019, STRATCOM Commander Gen. Hyten said “Four hundred ballistic missiles create a huge targeting problem for any adversary. The only way to get after four hundred hardened nuclear missiles is with a whole bunch of incoming weapons.”

What would “success” look like for the nuclear sponge?

The cost imposed on Russia if they attacked our ICBMs with theirs would indeed be terrible…but because we would most likely respond with an all-out nuclear attack, leading inevitably to the general destruction of both countries. But even if a president was wise enough not to retaliate against a surprise attack on our ICBMs, the biggest cost would be to us…to the 9 million people living in the five midwestern states with the silos, to much of our agricultural production, to the many more endangered by massive clouds of fallout. This doesn’t even take into account the healthcare crisis that would ensue, and the likely climate changes caused.

What is the US planning to do about ICBMs?

But the Pentagon is doubling down on this strategy. The current crop of ICBMs, the Minuteman III, are aging, and thus now would be a good time to begin phasing out this class of weapons. Instead of looking to finally get rid of these dangerous and obsolete Cold War relics, the U.S. has currently begun a massive program to “modernize” its nuclear forces, including replacing all the current ICBMs. The Pentagon plans to buy 659 new ICBMs, to be called the GBSD or Ground-Based Strategic Deterrent, at a projected total lifetime cost of $264 billion. Physicians for Social Responsibility created a calculator to determine how much we each pay for nuclear weapons.

Wouldn’t getting rid of ICBMs be politically difficult?

And it’s not as if this is a popular option. A survey in 2020 from the Federation of American Scientists found that 60% of Americans support alternatives to replacing all our ICBMs; 64% supported delaying the GBSD program and launching a review of options; only 18% were opposed to phasing out ICBMs altogether, as long as it included job support for those affected. Another 2020 study by the University of Maryland found that majorities of both Democrats and Republicans supported phasing out ICBMs.