What happens now that the US-Russia nuclear treaty is expiring?

After three decades of checking the global proliferation of nuclear weapons for both the United States and Russia, the New Strategic Arms Reduction Treaty (START) has come to its inevitable end. And that demise is sparking questions about what might fill the void the treaty leaves behind.

A continuation of earlier mutual arms control pacts, the New START Treaty represented the latest in more than half a century of U.S.-Russian cooperation to stem the tide of weapons of mass destruction — and its Thursday expiration marks the last of such endeavors. With no concrete plans for a similar nonproliferation pact to replace it, is the world now on the cusp of a Cold War-style atomic arms race?

What did the commentators say?

The dissolution of the New START Treaty, which regulated the amount of nuclear weapon-capable hardware deployed by both nations, comes at an “especially fraught time,” said Politico. Both Russia and China have been “expanding” their nuclear arsenals recently, and the Defense Department has launched a “series of internal meetings” to prepare for a “post-New START world.”

President Donald Trump, for his part, has “indicated that he would like a new deal” but said he “wanted it to include China.” But Chinese officials, said The New York Times, have “made clear they are not interested.” Broadly then, the treaty’s end signifies more than an expiration date, as multiple countries begin testing “new types and configurations of nuclear weapons” few could have envisioned when the Senate narrowly “ratified the New START treaty in 2010.”

Trump’s insistence that China be included in future antiproliferation treaties was “almost certainly a poison pill” intended to “stop any progress on renewing the existing treaty,” said The Atlantic. However hard two-party arms negotiations may be to achieve, “multilateral arms treaties are exponentially more difficult.” Complicating the situation further, Trump, in his second term, is surrounded by people who oppose most treaties as “annoying limitations on American power.”

The treaty’s end should “alarm everyone,” said Russian politician and former President Dmitry Medvedev, one of the original signatories to the 2010 deal. It is a “sobering comment” from someone whose “recent rhetoric has included nuclear threats,” said the BBC. Not only is the treaty’s expiration a “significant break in more than five decades of bilateral nuclear arms control,” said Chatham House, but by signaling a “move away from nuclear restraint,” the lapse ultimately makes the world a “more dangerous place.”

What next?

The loss of the New START Treaty is not only an end to “numeric limits” of nuclear arms but halts the “predictable flow of notifications, data exchanges, on-site inspections and other transparency mechanisms that reduced uncertainty and helped sustain predictability,” said Norwegian Institute for Defense Studies Professor Katarzyna Zysk to The Barents Observer. Absent that regularity, Russia will have to “plan against a U.S. force posture that is less observed,” leading to a “higher degree of uncertainty.”

The implicit message of allowing the treaty to lapse will be “received most clearly in Beijing,” said The Diplomat. While China’s nuclear arsenal is small in comparison to those amassed by the U.S. and Russia, the treaty’s end signals that “negotiated restraint among major powers is temporary and expendable.” Rather than curbing China’s atomic ambitions, the change only reinforces the “case for accelerating it in anticipation of a world without limits.”

The treaty’s end has also “sparked debate” among European leadership over “how to possibly shape” the continent’s nuclear defenses, said DW. In one outcome under consideration, the nuclear powers of France and the U.K. “extend their protection to other nations, such as Germany.”

If the White House thinks it “will be easy” to negotiate a “new ‘better’ treaty” now that this one has expired, “they are mistaken,” said Jennifer Kavanagh, the director of military analysis at the arms control advocacy group Defense Priorities, at The Guardian. Trump may be the ultimate dealmaker,” but when it comes to nuclear proliferation, he would have been “better off hanging on to the agreement” he let lapse before “trying to get a better one.”