The last nuclear arms agreement between Russia and the United States expired on Feb. 5.

For the first time since 1972, the world’s two most powerful nuclear countries have no limits on the deployment or the future of their arsenals. That leaves the world in a precarious place.

The United States and Russia each possess more than 5,000 nuclear warheads. Yet neither country was in a hurry to renew the New START Treaty, which was signed in 2010.

Russia’s leaders, preoccupied with their invasion of Ukraine, have sent mixed signals. They say they will honor the expired agreement only as long as the United States does so. Their stance certainly leaves plenty open to interpretation.

President Donald Trump wants an arms pact that also includes China. That is a wonderful goal. The more nuclear powers that sign onto an agreement to limit arms, the better. China has emerged as a superpower, and it should be part of negotiations.

But what would be wonderful should not prevent what is attainable. Just because China is not part of an initial agreement should not prevent the United States and Russia from leading by example.

Superpowers are far from alone in amassing nuclear weapons. North Korea has not abandoned its nuclear ambitions. Iran’s nuclear program remains a grave concern.

Meanwhile, our allies in Europe and potentially elsewhere are questioning whether they can count on America for defense or if they should expand their own nuclear capabilities.

No nuclear treaty has been perfect. There has always been room for skeptics to question whether all signatories are living up to their commitments and whether the agreements went far enough. But an imperfect treaty is better than no treaty.

The greater the number of nuclear weapons in our world, the greater the opportunity for one or more warheads to be used intentionally or inadvertently, to be seized by a rogue actor or terrorist organization, to become the spark that ignites a global catastrophe or to cause a humanitarian and ecological disaster.

Northern California has a long history of anti-nuclear activism. In the 1960s, a determined group of locals stopped PG&E from building a nuclear reactor at Bodega Head. Two decades later, Sebastopol voters overwhelmingly declared their city a nuclear-free zone. They enshrined an anti-nuclear message in the city code. That will not stop a bomb from going off, but it is a valuable statement of principle:

“No nuclear weapon shall be produced, transported, stored, processed, disposed of, nor used, within Sebastopol. No facility, equipment, supply or substance for the production, storage, processing, disposal or use of nuclear weapons, except radioactive materials for medical purposes, shall be allowed in Sebastopol.”

The Cold War is over, but the danger of nuclear annihilation has not faded. This year, the Bulletin of the Atomic Scientists moved the hands of the Doomsday Clock to 85 seconds before midnight, the closest to catastrophe in the clock’s 78-year history.

The North Bay residents who stopped a nuclear reactor and enshrined a nuclear-free zone into local law understood something that America’s current leaders have forgotten: A world without nuclear limits is not a negotiating position, and arms control is not a bargaining chip. Strike a new nuclear deal.