The news that the Biden administration will seek a five-year extension of the New Strategic Arms Reduction Treaty, or New START, is a welcome change from the Trump administration’s assault on nuclear arms control. But the Biden team should not be afraid to keep going and push arms control further.

Extending New START is an important win for U.S.-Russia strategic stability, which has frayed due to increasing animosity in the relationship. The bilateral agreement places limitations on the number of strategic nuclear warheads and delivery systems for both countries, but just as importantly contains provisions for inspections and information sharing that allow the two countries to keep tabs on one another’s nuclear arsenals and verify that the other is complying with the treaty.

While the prospects of a wholesale turnaround in U.S.-Russia relations is unlikely, the new administration’s willingness to buttress nuclear diplomacy so soon in its tenure is a promising sign. The treaty’s combination of limitations and transparency creates a degree of mutual trust between Washington and Moscow that has otherwise been in perilously short supply. Moreover, New START creates some predictability about the future size and composition of the Russian nuclear arsenal, which helps with U.S. nuclear planning and reins in arms-racing behavior.

In essence, the treaty creates conditions in which neither country has the incentive to build out its nuclear forces to gain an advantage over the other. New START does not prevent U.S.-Russia nuclear competition, but it sets guardrails that prevent that competition from spiraling out of control.

Like all treaties, New START is not without its faults. Shorter-range “tactical” nuclear weapons are not covered, and some critics have argued that New START’s verification regime is not as robust as the one established by the treaty that preceded it. The Trump administration seized on these faults as well as fears about China’s growing nuclear arsenal as New START’s expiration date drew closer.

Instead of offering Russia a five-year extension, the Trump administration’s negotiating team proposed a shorter extension that would buy time for the United States and Russia to negotiate a more extensive treaty that addressed New START’s perceived shortcomings. If Moscow refused a short-term extension, New START would simply expire without a replacement in place. President Donald Trump’s withdrawals from the Intermediate-Range Nuclear Forces Treaty, Iran nuclear deal and Open Skies Treaty lent credibility to U.S. threats to walk away from New START, but the administration failed to get Russia to agree to its terms.

With the offer to seek a five-year extension to New START, the Biden administration is signaling a clear departure from Trump’s approach to arms control, which emphasized tearing up agreements rather than creating new ones. While no treaty is without faults, New START effectively advances U.S. security interests and reduces nuclear risks with Russia in ways that supporters of a grand strategy of restraint should support.

While today is a good day for arms control, its future is far murkier. Extending New START and returning to some agreements that the Trump administration left — especially the Iran nuclear deal — are good, early priorities for the Biden administration. However, moving arms control into the future will require more creative thinking and a willingness for the United States to consider potentially painful trade-offs in the pursuit of nuclear stability.

If the Biden administration wants to make progress on nuclear diplomacy with North Korea, for example, it will have to move away from the denuclearization-or-bust approach favored by previous administrations. Adjusting U.S. expectations and strategy away from denuclearization and toward arms control has a greater likelihood of putting limits on North Korea’s nuclear program than continuing to focus on complete denuclearization. Yet in the process, President Joe Biden would likely have to make concessions on important U.S. interests such as military exercises and sanctions, and consider ending the Korean War.

Similarly difficult trade-offs will likely be required if the Biden administration wants to begin working with Russia to lay the groundwork for New START’s successor treaty. Securing future limitations on Russian nuclear weapons and delivery vehicles will likely require the United States to consider limitations on its missile defense capabilities. The United States has been categorically opposed to missile defense limitations since leaving the Anti-Ballistic Missile Treaty in 2002, but such capabilities play a major role in encouraging Russia’s development of new nuclear weapons.

A five-year extension of New START is an encouraging sign that the Biden administration will try to repair the damage that Trump did to arms control. Extending the treaty will remove a looming foreign policy crisis from Biden’s list of concerns at a time when the new administration’s attention must be on ending the COVID-19 pandemic. If Biden is bold, this can be the beginning of a new era of U.S. interest in arms control.

Eric Gomez is the director of foreign policy studies at the Cato Institute.

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