ARMS CONTROL treaties are only as good as the willpower of the countries that sign them. Binding, verifiable agreements help reduce dangers but only when the signatories adhere to them. What’s happening now is a crisis of confidence that is causing the old arms control system to break down. There’s plenty of blame to spread around, including Russia and the United States.

The latest example is President Trump’s decision to pull out of the Open Skies treaty, a modest confidence-building agreement signed in 1992 that went into force in 2002. With 34 signatory nations, it has proved a useful pact, allowing signatories to carry out short-notice, unarmed overflights of other countries with airplanes using sensors that detect and record military activity on the ground. The images aren’t as detailed as U.S. satellites can obtain, but benefit allies that lack the satellites.

The administration says it has lost confidence in Russia’s adherence to the treaty. The reasons given in a briefing May 21 include complaints about Russia’s behavior elsewhere. State Department Assistant Secretary Christopher A. Ford faulted Russia for its military actions against Georgia and Ukraine, including the seizure of Crimea, and for forsaking the Conventional Forces in Europe Treaty. Special Presidential Envoy for Arms Control Marshall Billingslea raised the Novichok poisoning. Each of these has validity. But to pile them atop the Open Skies treaty is to impose a burden the pact was never intended to carry.

The administration also resurfaced complaints about Russian limitions to treaty overflights. These are real implementation issues, but they do not defeat the purpose of the treaty, and should be resolved — as they have been in the past — by the treaty’s Consultative Commission. One issue, on flights over Kaliningrad, was in the process of being worked out. Another, about flights near Georgia and the enclaves of Abkhazia and South Ossetia, is linked to the larger dispute over Russia’s claim they are independent states, which most of the world does not recognize. This is hardly a treaty-breaker. Secretary of State Mike Pompeo declared that Russia has “weaponized” the treaty by “targeting critical infrastructure in the United States and Europe with precision-guided conventional munitions” based on treaty imagery. But Mr. Ford pointed out “it’s not a violation of the treaty to collect imagery of civilian infrastructure,” although he called it “problematic.” Has anyone tried to resolve this with Moscow? Treaty signatories Belgium, the Czech Republic, Finland, France, Germany, Italy, Luxembourg, the Netherlands, Portugal, Spain and Sweden said the pact remains “functioning and useful.”

Mr. Billingslea announced that talks with Russia on arms control will resume soon and “our expectation” is that China will join. Having China at the table is a worthwhile goal. So far, Beijing has refused. It should be constantly asked, but China’s answer should not hold up extension of the New Start strategic nuclear weapons treaty between Russia and the United States, which expires next year. The treaty serves the interests of both countries. Both ought to show some willpower and extend it for five years.

Read more: