In a post-Cold War world, uncertainty surrounds nuclear triad.

• Author: Insinna, Valerie

* The world is a very different place than it was in the 1950s, when the United States needed thousands of nuclear warheads and three ways to deliver them on target to keep the Soviet Union at bay.

More than two decades since the fall of the Iron Curtain and the end of the Cold War, the U.S. military still maintains all three legs of the nuclear "triad"--heavy bombers, submarines and land-based intercontinental ballistic missiles. Though both the United States and Russia have agreed to gradually reduce the number of deployable warheads in their strategic arsenals, a polarizing argument remains over whether the military needs or can afford each of the three methods of deploying them.

The Soviet Union is no more, but Russia remains the only nation with a nuclear arsenal that even remotely rivals the United States' capability. While China is nuclear capable and has a large military, that nation's weapons are primarily conventional. It does not have enough nuclear weapons to launch a first strike that would realistically threaten U.S. nuclear capability, given its three redundant legs.

The 2010 nuclear posture review recognized that Russia will remain an important bellwether in guiding the size of the U.S. nuclear arsenal.

"Because of our improved relations, the need for strict numerical parity between the two countries is no longer as compelling as it was during the Cold War," the NPR stated.

The U.S. Nuclear Employment Strategy released June 19, which laid out the Obama administration's plans for the arsenal and how it is deployed, echoed the 2010 NPR.

"The international security environment has changed dramatically since the end of the Cold War," the strategy said. "The threat of global nuclear war has become remote, but the risk of nuclear attack has increased" because of proliferation and the rise of rogue nations and non-state actors.

Though the likelihood of nuclear war is small, and only Russia has the ability to counter the United States, the strategy called for maintaining the nuclear triad of submarines, bombers and land-based ICBMs.

Proponents of the triad, like Peter Huessy, a senior fellow of national security affairs at the American Foreign Policy Council, insist all three legs are necessary.

"Survivability, recallability and stability. You need all three of these things to maintain an effective deterrent," Huessy told National Defense.

"The issue with the triad is how to maintain a secure, credible, survivable force at a reasonable price that gives us options and keeps them open," he said. "You're going to have bombers anyway ... and you want something you can recall because that gives you an enormous amount of leverage. You don't have to commit."

The U.S. Nuclear Employment Strategy reflected Huessy's position.

"Retaining all three triad legs will best maintain strategic stability at reasonable cost, while hedging against potential technical problems or vulnerabilities," the strategy read. "These forces should be operated on a day-to-day basis in a manner that maintains strategic stability with Russia and China, deters potential regional adversaries and assures U.S. allies and partners."

Gen. Garrett Harencak, commander of the Air Force Nuclear Weapons Center, argued in favor of retaining all three delivery vehicles.

"I don't come to you as a Cold War zealot," Harencak said at a recent breakfast hosted by Huessy. "The legs of the triad that the United States Air Force, in conjunction with the United States Navy, provide are as relevant today as it always has been, regardless of what the particular numbers are, regardless of treaties or whatever."

"Ladies and gentlemen, it's not either/or," he said of the three legs. "It all works together. It has worked together and has been an absolutely vital part of our defense for decades and it will continue."

The reason the United States ultimately ended up with three delivery systems for nuclear warheads was more a function--in the earlier clays of the Cold War--of...