America’s Nuclear Deterrent–And Defenses–Are Eroding Fast

The president hasn’t fulfilled his promises to modernize, with potentially dire results.

Thirty years ago, on March 23, 1983, President Ronald Reagan changed history by announcing his commitment to developing and deploying a missile defense to protect America from Soviet missile attack. He said, “I’ve become more and more deeply convinced that the human spirit must be capable of rising above dealing with other nations and human beings by threatening their existence.”

The result was the Strategic Defense Initiative, an unprecedented scientific effort to develop the capability to intercept and destroy attacking enemy missiles. The Soviets knew they could not compete with SDI, and Reagan’s initiative has been credited with hastening the collapse of the Soviet Union.

Fast forward to today. What is the status of missile defense and the nuclear weapons that remain the foundation of the U.S. strategic deterrent? Sadly, despite great scientific and technological success, both programs are in jeopardy. Neither is likely to fare well under President Obama, who advocates “nuclear zero” and is no fan of missile defense. The president is on course to systematically reduce America’s capabilities in both areas despite specific commitments he made while securing bipartisan support for the 2010 New Strategic Arms Limitation Treaty with Russia.

Recent North Korean nuclear and long-range missile tests prompted the administration to add 14 ground-based interceptors in Alaska—where they will be part of a system that uses radar and missiles to destroy incoming enemy warheads—in addition to the 30 already deployed on the West Coast to defend the homeland. Yet this merely gets us back to the numerical level planned during the Bush administration—and without the technological improvements in ground-based interceptors, or GBIs, that the Bush administration supported.

As a result, the U.S. national missile defense will continue to rely on obsolete 1980s “kill vehicle” technology involving kinetic energy and small warheads. At 44 GBIs, the system should be effective against the current threat from North Korea, but not against an attack from countries like Russia and China with more robust and mature capabilities.

The U.S. has canceled the final phase of the Europe-based missile-defense system, which was to have included NATO allies such as Poland as the hosts of sensors and other elements of the system. This will please Russia. But it means that the Aegis system the Navy uses to track enemy missiles and guide American ones will be less capable of protecting Europe—from Iran, for instance—and offer even less protection for the U.S. The assurance of deploying the final phase of missile defense in Europe was the Obama administration’s pretext for capping the improvement of America’s GBI system.

On missile defense, then, the U.S. is now stuck with numbers and technology capable of dealing only with low-level threats. The situation doesn’t look any better on strategic nuclear deterrence. U.S. modernization programs—to extend the life of America’s aging ballistic nuclear warheads and modernize its “triad” approach to defense against nuclear attack—are in trouble.

Intercontinental ballistic missiles are the first leg of the triad. Although Russia is preparing to field a new generation of intercontinental ballistic missiles (one type of which can carry as many as 15 warheads), the Obama administration is still studying whether to develop its own modernized ICBMs.

The planned replacement of the Ohio-class nuclear-ballistic-missile submarine—the foundation of the sea-based leg of the triad—has been delayed for two years, leaving the force with only 10 boats. As to the third leg, the strategic-bomber force, no decision has been made on whether the next generation will even be capable of delivering nuclear weapons.

Meanwhile, a comparison of the 2010 and 2013 budgets submitted by the Energy Department and National Security Agency indicates that the five-year budget for these modernizations has been cut by some $4.4 billion. That’s the same amount President Obama had agreed to add to secure Senate support for the New Start treaty in 2010.

Money wasn’t the only promise tied to New Start. The building of a modern Chemical and Metallurgy Research Replacement facility for handling plutonium was so critical to senators that it was specifically included in the Treaty Resolution of Ratification and in the president’s message to the Senate upon entry of the treaty into force. Yet that facility, so essential for modernization, has been delayed at least five years—tantamount, some say, to killing it.

The president cannot be unaware of the implications of such delays. Mr. Obama’s own Nuclear Posture Review confirmed that the U.S. cannot reduce warheads under New Start (or beyond) without completing the infrastructure and the rest of the nuclear modernization program.

The president also risks confrontation with the Senate if he follows through on a reported plan to seek further reductions with Russia by executive agreement rather than another treaty. He has already soured relations with some senators who supported New Start on the basis of his now broken budget commitment.

We have come a long way since President Reagan launched SDI. Thirty years ago, we had a very robust nuclear deterrent to make up for the lack of missile defense. President Obama’s antipathy to both missile defense and our nuclear deterrent risks leaving the U.S. and its allies vulnerable not just to attack, but also to nuclear blackmail and proliferation. How much will it cost in the future to make up for the folly of today?

Mr. Kyl, until this year a Republican senator from Arizona, is now a senior adviser to the law firm of Covington & Burling in Washington, D.C.