Editor’s note: This article was originally published by The Fletcher Forum of World Affairs.

The United States and Russia have just begun the third year of implementing the New Strategic Arms Reduction Treaty (New START). When the treaty takes full effect in February 2018, each country will be limited to no more than 1,550 deployed strategic warheads on 700 deployed strategic missiles and bombers. That represents progress, but more can and should be done.

For instance, New START does nothing to constrain non-deployed (reserve) strategic warheads or any non-strategic (tactical) weapons; it covers only about thirty percent of the total U.S. nuclear arsenal. It’s time to bring these weapons to the table. Additionally, twenty years after the end of the Cold War, do the United States and Russia require such large deployed strategic forces?

Recent press reports suggest the Obama administration is ready to answer this question and also bring the “off the table” weapons into the equation. The reports said the administration has concluded that it would be able to reduce the U.S. arsenal to 1,000-1,100 deployed strategic warheads and 2,500-3,500 total nuclear weapons, “without harming national security.” This would be an important step forward. An agreement along these lines could mean a thirty percent cut in deployed strategic warheads from the New START level and could require up to a fifty percent reduction in total U.S. and Russian nuclear arsenals.

Such a treaty would be in the U.S. interest for several reasons. First, it would reduce the nuclear threat to the United States. It would also promote a more stable nuclear balance with Russia, that is, a balance in which neither side has incentives to use nuclear weapons first in a crisis. The lower limit could lead the Russians to conclude that they do not need their proposed new heavy intercontinental ballistic missile (ICBM), which would threaten U.S. ICBMs in their underground silos. At the same, a new heavy ICBM would itself present a lucrative target for preemptive attack in a crisis—a problem noted by a number of Russian experts critical of the planned missile.

Second, by bringing all nuclear arms into the negotiation, a new U.S.-Russia treaty would cover non-strategic nuclear weapons, which would be welcomed by U.S. allies in Europe and Asia who feel threatened by Russian tactical weapons. Moreover, by submitting all of their arsenals to limits, Washington and Moscow would be better positioned to then expand the arms control process to include other nuclear weapons states. That is because the arsenals of Britain, France, China, India, Pakistan, Israel and North Korea contain many non-strategic nuclear arms.

Third, a new treaty that reduced U.S. and Russian nuclear forces could mean cost savings for a strained defense budget. The savings in operating costs in the near term might not be that large, but lower limits could mean substantial savings in the longer term, as the United States recapitalizes its strategic forces. For example, the U.S. Navy estimates that the replacement submarines for the Ohio-class ballistic missile submarine will cost $6-7 billion each. The Navy hopes to cut that cost, but the recent history of naval shipbuilding suggests the ultimate price tag of new vessels is often higher than initial estimates. A treaty that reduced the need for even two submarines would eliminate the cost of building and then operating them for up to forty years.

Fourth, further U.S. and Russian reductions would bolster those countries’ credentials in raising the bar against nuclear proliferation. A new treaty would not cause North Korea or Iran to change course. It could, however, empower American diplomacy to persuade third countries to up the pressure, including sanctions, on nuclear proliferators.

Finally, a new U.S.-Russian treaty could contribute to an improved broader relationship between the two countries. It could also contribute to better relations with China.

Negotiating and concluding such a treaty would by no means be easy. It is not clear that the Russians are prepared to deal. New tensions have afflicted the bilateral relationship over the past year, and President Putin seems in a cantankerous mood. But Moscow may have incentives to engage. The United States is better placed to sustain its strategic forces at New START levels, while the Russians will have to build new missiles to maintain their forces at the negotiated limits—and they may face tough budget decisions of their own.

There should be a better idea of whether the Russians want to engage after National Security Advisor Donilon’s visit to Moscow later this month, during which arms control undoubtedly will rank near the top of the agenda. The odds of getting a new agreement may not be all that high, but the pay-off in terms of a safer America and enhanced global security makes it a proposition worth testing.