Russia used cloud seeding over Belarus to prevent Moscow from receiving radioactive rainfall (fallout) from the Chernobyl nuclear reactor meltdown.

In 1986, the Soviet minister of hydrometeorology, Yuri Izrael, had a regrettable decision to make. It was his job to track radioactivity blowing from the smoking Chernobyl reactor in the hours after the 26 April explosion and deal with it. Forty-eight hours after the accident, an assistant handed him a roughly drawn map. On it, an arrow shot north-east from the nuclear power plant, and broadened to become a river of air 10 miles wide that was surging across Belarus toward Russia. If the slow-moving mass of radioactive clouds reached Moscow, where a spring storm front was piling up, millions could be harmed. Izrael’s decision was easy. Make it rain.

So that day, in a Moscow airport, technicians loaded artillery shells with silver iodide. Soviet air force pilots climbed into the cockpits of TU-16 bombers and made the easy one-hour flight to Chernobyl, where the reactor burned. The pilots circled, following the weather. They flew 30, 70, 100, 200km – chasing the inky black billows of radioactive waste. When they caught up with a cloud, they shot jets of silver iodide into it to emancipate the rain.

In the sleepy towns of southern Belarus, villagers looked up to see planes with strange yellow and grey contrails snaking across the sky. Next day, 27 April, powerful winds kicked up, cumulus clouds billowed on the horizon, and rain poured down in a deluge. The raindrops scavenged radioactive dust floating 200 metres in the air and sent it to the ground. The pilots trailed the slow-moving gaseous bulk of nuclear waste north-east beyond Gomel, into Mogilev province. Wherever pilots shot silver iodide, rain fell, along with a toxic brew of a dozen radioactive elements.

If Operation Cyclone had not been top secret, the headline would have been spectacular: “Scientists using advanced technology save Russian cities from technological disaster!” Yet, as the old saying goes, what goes up must come down. No one told the Belarusians that the southern half of the republic had been sacrificed to protect Russian cities. In the path of the artificially induced rain lived several hundred thousand Belarusians ignorant of the contaminants around them.