President Obama has started planning a new round of nuclear arms negotiations with the Russians. He apparently hopes to rid the world of nuclear weapons. This indeed could be an opportune time to rethink arms control. And who doesn't want a world safe from nuclear Armageddon?

The real question is: Which arms control strategy can best make this a reality and also achieve security? That's the ultimate purpose of U.S. policy.

Surely a world without nuclear weapons is safer than one with them. But this insight is not particularly helpful for guiding arms control talks. Nuclear arms exist and, regardless of what we may want, many countries want to keep them. An exclusive focus on eliminating all nuclear weaponry distracts from the larger, more important goal of security. After all, the reason to rid ourselves of nukes is to make us safe, not simply to cut up missiles. Someday we may reach the point where nuclear missiles are no longer usable, but how we get there may require more than simply trying to ban them outright.

We need to think about arms control differently. Rather than making the process an end in itself, we should focus on the outcome of making the world safer. Strategic forces should be mainly defensive in nature, in keeping with the principle of nonaggression. Think of an arms control agreement as a sort of nonaggression pact in terms of strategic forces. The purpose of these forces would be first to deter offensive attacks and then to defeat them, should that fail.

Arms control agreements can steer this process, encouraging both sides to reduce their offensive missiles and to make sure the remaining missiles don't purposely target population centers. Over time, strategic defenses against offensive missiles would be integrated into America's and Russia's force postures, even to the point where the two nations would deploy and operate strategic defenses cooperatively.

The road map to such an outcome is outlined in a forthcoming paper by Heritage analyst Baker Spring and Andrei Shoumikhin, an expert on Russian arms control policy at the National Institute for Public Policy. They recommend that we:

• Let the Strategic Arms Reduction Treaty expire. START, ratified in 1994, expires in December. It would be best to let it lapse rather than negotiate a new agreement with Russia under a tight deadline, as rushed agreements on matters as technical as arms control almost always end up flawed. On Wednesday, however, Mr. Obama decided to do exactly the opposite, declaring at a London meeting with Russian President Dmitry Medvedev that negotiators have been told to have the broad outlines of a new treaty ready by the end of July.
• Negotiate a verification and transparency protocol to the Strategic Offensive Reductions Treaty, better known as the Moscow Treaty. This treaty limits nuclear forces to levels below those allowed by START. Although it remains in force until 2012, the Moscow Treaty uses verification and transparency provisions taken from START, which are not suited to verifying the reductions it requires. START limits warheads on the basis of the capacity of strategic delivery systems; the Moscow Treaty directly limits all operationally deployed warheads. Correcting this should be the first order of business for arms control talks with the Russians.
• Propose a joint declaration with Russia to "protect and defend." Once the agreement on verification and transparency is completed, the U.S. and Russia should agree to an outline for future negotiations dedicated to a "protect and defend" strategy. Taking the form of a joint declaration, the outline would guide subsequent negotiations on arms control and strategic cooperation with the purpose of transitioning strategic forces to a defensive posture and away from retaliation-based offenses. From there, the U.S. and Russia could engage in negotiations on other discrete problems. The goal throughout: to move both nations - and, eventually, other nuclear-armed states - away from Cold-War "balance of terror" strategies.

What kind of agreements might the new defensive strategy produce? How about a second Strategic Offensive Reductions Treaty (SORT II) that would cut the number of deployed warheads below that which is allowed by the Moscow Treaty. SORT II could reduce population-busting, inaccurate systems and encourage the use of strategic defenses. Some modernization of offensive nuclear weapons would still be necessary to deter those posing a threat of nuclear attack.

U.S.-Russia arms control negotiations could proceed in concert with a strategic defense cooperation treaty or be conducted after the treaty was signed. The cooperation treaty agreement could cover defenses against nuclear, biological and chemical arms and their ballistic missiles, cruise missiles and aircraft systems. Subsequent cooperative talks could address other concerns, such as countering nuclear-armed terrorism.

All these negotiations have one purpose: to make the world safer. A defensive strategy that devalues offensive weapons has a far better chance of eliminating them than trying to ban them outright. It not only deals more realistically with the world of strategic weaponry, it also focuses on what arms control is supposed to be about - protecting Americans and other innocent people from nuclear attack.