We may well be on the cusp of another round of deep cuts — 50 percent or more — to the American nuclear arsenal. While nuclear weapons occupy a unique niche in America’s arsenal, they are fundamental to the nation’s strategic planning. Fewer nukes can mean more money for other national security needs, or for other domestic spending. So I asked the head of the sober Arms Control Association to offer his view of what should happen. Given the fairly close links between the association and the administration, you may well find these same arguments being deployed later. The Editor.

In the 20 years since the end of the Cold War, successive U.S. and Russian presidents have gradually reduced the size and salience of their enormous nuclear stockpiles, which remain by far the largest of any country. Nevertheless, the size of each country’s arsenal far exceeds what is necessary to deter nuclear attack by the other or by one of the world’s other nuclear-armed states.

Both sides can and should go lower.

Even under the New START treaty, approved in 2010, each country is still allowed to deploy 1,550 strategic nuclear weapons on 700 missiles and bombers until the year 2021. Under current plans, thousands of additional warheads would held in reserve. Today, each nation’s total nuclear stockpile exceeds 5,000 nuclear bombs. Unless they adjust their thinking, both countries will spend hundreds of billions of dollars to maintain and modernize these large nuclear force levels for 20 to 30 years to come.

Press reports this week confirm that President Barack Obama is poised to review the presidential nuclear “guidance” that determines U.S. nuclear war plans, the target lists, and the number of nuclear weapons and delivery systems “required” to hit them. While no decisions have been made yet, Mr. Obama will reportedly consider options developed by the Pentagon that could eventually lead to a reduction in the number of deployed nuclear weapons of 50 percent or more.

That’s welcome news. A wide-range of national security and military experts believe that this review is overdue and that fundamental changes are in order.

The Obama administration’s 2010 “Nuclear Posture Review Report” provides a new framework for the steps the President should now take to reduce the role and number of U.S. nuclear weapons and eliminate outdated Cold War thinking. The document states that “the fundamental role of U.S. nuclear forces is to deter nuclear attacks against the U.S. and our allies and partners.” That is an important shift away from the Cold War-era strategy of being prepared to “prevail” in a protracted nuclear exchange with the Soviets involving thousands of city-busting nuclear bombs, and also to be prepared to use nuclear weapons against conventional military threats.

In line with this new approach, the United States (and Russia) could reduce their overall nuclear stockpiles substantially-to 1,000 warheads each– and still retain sufficient firepower to deter nuclear attack by any current or potential adversary. Other than Russia and the United States, no other country deploys more than 300 strategic warheads. China possesses just 40 to 50 nuclear warheads on intercontinental-range missiles. Iran does not have nuclear weapons and North Korea’s arsenal is limited in size and range.

And given the reality that the chance of a bolt-from-the-blue nuclear attack from Russia is near zero and far less likely today than it was during the Cold War, the nuclear force required to deter such an attack is far less than it was then. Joseph Stalin might have been willing to sacrifice tens of millions of Russians in a nuclear exchange, but Vladimir Putin would not. Just one U.S. nuclear-armed submarine could devastate an entire nation and kill millions.

A 2007 Arms Control Association report, “What Are Nuclear Weapons For?” by Stanford physicist Sidney Drell and James Goodby of the Hoover Institution concluded that the United States can and should achieve move to a smaller force of 500 deployed and 500 nondeployed strategic warheads on a mainly submarine-based “triad” of nuclear delivery systems within the next few years.

A 2010 study by three Air Force analysts in Strategic Studies Quarterly concluded that the United States could deter nuclear attack with a relatively smaller number of survivable, reliable weapons dispersed among missile silos, submarines, and airplanes.” They argue that such a force might number only 311 nuclear weapons.

There are a number of changes to nuclear weapons plans President Obama should consider to move in the right direction. He could eliminate entire target categories from the current nuclear war plan, which now include a wide range of military forces, nuclear weapons infrastructure, and military and national leadership targets, and war-supporting infrastructure, mainly in Russia. These targeting assumptions were developed decades ago to deplete war-fighting assets rather than ensure there is a sufficient retaliatory capability to deter nuclear attack in the first place.

Obama should also direct war planners to discard old assumptions for how much damage must be accomplished to ensure that a target is destroyed. Current plans require hitting many targets with more than one nuclear weapon. To deter a nuclear attack, adversaries need only realize the United States is capable of reducing key targets to radioactive rubble rather than a fine dust.

The nuclear policy review also gives President Barack Obama the chance to eliminate the Cold War practice of keeping nuclear weapons ready to launch within minutes. During the 2008 presidential campaign, Obama said the practice is “outdated” and “increases the risk of catastrophic accident or miscalculation.” Indeed, a reliable and credible U.S. nuclear deterrent does not require the ability to retaliate immediately if U.S. nuclear forces and command and control systems can survive an attack — and they can.

Obama can and should make it clear that the United States no longer will develop or exercise plans for rapid launches and will replace such plans with new ones that would allow the president to delay a response to a nuclear attack for days. He should invite Russia to make reciprocal changes to its nuclear posture.

Some of the administration’s critics may — incorrectly — assert that given the risk that nuclear weapons will spread, further reductions in our arsenal would be unwise. But maintaining overpowering nuclear forces does not deter nations, such as Iran or North Korea, or terrorist actors to abandon their pursuit of these weapons. We must recognize that the other pressing security threats we face today – terrorists, short and medium-range ballistic missiles, and cyberattack –simply cannot be dealt with by means of a large nuclear arsenal. And all of the United States major allies support further steps to reduce U.S. and Russian nuclear stockpiles.

Maintaining an excessively large nuclear force could also push China to alter increase the size and lethality of its relatively limited long-range nuclear force. For its part, Russia will be hard pressed to deploy 1,550 strategic warheads unless it undertakes an expensive ballistic missile modernization effort. Rather than induce Russia to build up, it is in the security and financial interests of both countries to pursue further, parallel nuclear reductions.

Since the end of the Cold War, U.S. presidents have understood the logic and value of reducing nuclear overkill. During George H. W. Bush’s four years in office, the total U.S. arsenal was shrunk from about 22,200 weapons to 13,700 — a 38 percent cut. In George W. Bush’s eight years, the U.S. arsenal dropped from about 10,500 weapons to just over 5,000 — about 50 percent fewer.

Now is the right time for President Obama to provide the leadership necessary to discard dangerous Cold War-era nuclear war plans, slash costly nuclear arsenals, and redirect taxpayer dollars to more pressing U.S. security needs.

Daryl G. Kimball is executive director of the independent Arms Control Association in Washington, D.C.