SPY PLANES ordinarily have to sneak into a country’s air space and risk getting shot down. Under the Open Skies treaty, they can saunter in with three days’ notice—and the pilots can enjoy a cup of coffee and a hot meal on the ground. The pact was agreed on in 1992 among 34 countries, each of which may fly unarmed reconnaissance flights over any part of another. More than 1,500 flights have been conducted to date. But on May 21st Mike Pompeo, America’s secretary of state, said that the United States would pull out of the accord, giving the requisite six months’ notice. John Bolton, America’s national security adviser until last September, hailed the news as “another great moment in arms control history”. Others view it as a calamity that makes the world more dangerous.
The treaty itself is a remarkable example of what arms-controllers call “co-operative monitoring”, a means of checking whether rivals are living up to various agreements, from nuclear pacts to rules governing military exercises. Each country is allowed to conduct an agreed number of flights on 72 hours’ notice, with a day’s notice of the precise flight path. Russia has often whizzed over the White House and, in 2017, irritated Donald Trump by flying over his golf course in New Jersey, according to the New York Times. No fancy spy gizmos are allowed. Planes may only carry cameras of 30cm-resolution, most of which use black and white wet-film. The resulting photos must be shared with any signatory who wants them. Personnel from the host state, sometimes half a dozen or more, may fly aboard the plane too, ensuring that everything is kosher.
America has made good use of the treaty, carrying out 201 flights since 2002, the vast majority of them over Russia or its ally Belarus. But hawks in the Trump administration complain that Russia has bent the rules. In his statement announcing America’s pull-out, Mr Pompeo levelled two main charges. The first was that Russia was “unlawfully denying or restricting Open Skies observation flights whenever it desires”. He pointed to Russian restrictions on flights near its border with Georgia, over Kaliningrad, an exclave wedged between Poland and Lithuania, and over military exercises last year.
His second complaint was that Russia was using flights to gather tactical military intelligence. “Moscow appears to use Open Skies imagery in support of an aggressive new Russian doctrine of targeting critical infrastructure in the United States and Europe with precision-guided conventional munitions,” he said. Mr Pompeo allowed that America might “reconsider our withdrawal should Russia return to full compliance”.
European officials, who had pleaded with the administration to remain in the treaty, are aghast. They acknowledge that Russia has not implemented the accord perfectly, but insist that the issues could have been resolved with time and effort. Earlier this year, for instance, Russia allowed flights over Kaliningrad to resume. Former American officials also push back at the view that the flights boost Russian targeting. “The information Russia gleans…is of only incremental value in addition to Russia’s other means of intelligence gathering,” noted Terry Benedict, a retired vice-admiral, in a congressional hearing in 2017.
What is lost is more significant. There are few occasions left where American and Russian airmen can chew the fat over the Rockies or Siberia. Flights are “a normalising, collegial, routine which builds trust,” says Melissa Hanham of the Open Nuclear Network, an NGO. More importantly, notes James Acton of the Carnegie Endowment, a think-tank, America’s withdrawal is “a win for Russia, which has a number of spy satellites”, and “an FU to allies in Europe, many of which don’t”.
Of course, allies could ask America for satellite images. But these, unlike Open Skies photos, tend to be highly classified and, for that reason, cannot be shared as freely. General James Mattis, Mr Trump’s first defence secretary, once noted that Open Skies imagery was “a key visual aid” during Russia’s invasion of Ukraine in 2014. Although some of the gap may be filled by commercial satellite imagery, which did not exist when the treaty was signed 28 years ago, planes can spot things concealed from ordinary satellite sensors. Open Skies aircraft may carry thermal-imaging cameras, for instance, which can detect such things as whether an aircraft is fully fuelled or bone dry.
A pressing question is now whether the treaty can survive America’s departure. On the one hand, Russia will no longer be able to fly over America, while still being subject to overflight from any one of America’s numerous friends in Europe. On the other hand, says Alberto Muti of VERTIC, an NGO that promotes the verification of international agreements, Russia still gets to monitor all of Europe, and will initially have more quota flights to do so (this will need to be reviewed by all parties). Moreover, because many European states lack their own specialised aircraft, and have piggybacked on American missions, NATO as a whole loses capacity to conduct flights. Russia is likely to remain in the treaty for the time being, at least.
The breakdown of Open Skies represents another blow to the architecture of global arms-control, which has had a torrid few years. In 2018 Mr Trump left a multinational nuclear deal with Iran. Last year he abandoned a cold-war missile pact which Russia had probably violated. Next year he may walk away from the last remaining cap on American and Russian arsenals, the New START treaty. As these accords crumble, so too do their intricate provisions for verification, such as inspections, data exchanges and, in the case of Open Skies, overflights. That makes each country ever more blind to what the others are doing—and, perhaps, more likely to assume the worst. On May 21st Marshall Billingslea, America’s envoy for arms control, hinted at Mr Trump’s willingness to run an arms race: “We know how to spend the adversary into oblivion. If we have to, we will, but we sure would like to avoid it.”