Today's nuclear missiles, like these ones, should be historical artifacts. Source: Central Press via Getty Images
Today's nuclear missiles, like these ones, should be historical artifacts. Source: Central Press via Getty Images

Intercontinental ballistic missiles armed with nuclear warheads are the most fearsome weapons devised by man -- and today among the least useful. In his review of the U.S. nuclear arsenal, prompted by personnel problems, U.S. Defense Secretary Chuck Hagel shouldn't be afraid to step back and acknowledge the obvious: Land-based missiles are obsolete.

ICBMs embody the Cold War logic of “mutually assured destruction.” The sense that this doctrine is no longer relevant to modern defense has apparently infected the Air Force units that operate the missiles. Reports of drug use, drunkenness and cheating on proficiency tests led Hagel to call for the review. This wasn't the first such scandal. The underlying problem is that ICBMs have become a weapon without a purpose.

At a time of budget stringency, the Pentagon expects to spend about $1 trillion over the next 30 years on modernizing its aging nuclear "triad" of land-based missiles and nuclear-armed bombers and submarines. Almost all of these weapons are nearing the end of their planned operational lives. It's a good moment to think afresh about cost-effectiveness in nuclear deterrence.

The Air Force badly wants a fleet of new long-range bombers costing more than $100 billion to replace its B-52s and B-2s. Strategic bombers have the advantage of being recallable: They can be launched to signal U.S. resolve or intent in a crisis, and ordered home once the message is received. They are also dual-use platforms, capable of carrying nuclear or conventional bombs and missiles.

The 14 Ohio-class ballistic-missile submarines are also reaching the end of their anticipated service. The Navy wants new ones at a cost of more than $6 billion apiece. Submarines are the least vulnerable part of the triad, able to patrol the world’s oceans undetected and respond with a devastating counterattack even if U.S. bomber and ICBM forces were destroyed. But they're expensive to build and operate.

Then there's the Air Force’s aging force of 450 Minuteman III ICBMs. Because they sit in fixed silos, they're individually vulnerable. Their sheer numbers and dispersal make them a credible deterrent, but they can't be used flexibly: It's Armageddon or nothing. Under their current life extension the Minutemen IIIs will last to about 2030, and the Air Force has no plan yet for a replacement.

There's no need to replace them. This portion of the triad can be dispensed with. The land-based missiles are the least cost-effective, and their drawbacks will only loom larger as arms-control efforts move forward. Under the New START agreement, the U.S. and Russia are limited to 1,550 deployed warheads and 700 deployed missiles and bombers, and President Barack Obama has already said he's willing to reduce nuclear forces by an additional third (to roughly 1,000 to 1,100 deployed warheads). At lower numbers of warheads and launchers, the relative vulnerability and inflexibility of ICBMs matter more.

Spending on bombers and submarines makes better sense than spending on ICBMs, but savings that don't compromise security are possible there, too. Hagel's review should propose some.

Obama rightly says he wants to decrease U.S. reliance on nuclear weapons. Achieving that goal will require abandoning some of the orthodoxies of mutually assured destruction. Chief among these is the idea that nuclear deterrence requires maintaining enough weapons to “make the rubble bounce” on doomsday. That's a great way to waste money, but has nothing to do with effective defense.

To contact the senior editor responsible for Bloomberg View's editorials: David Shipley at davidshipley@bloomberg.net.