It began as a gray and muddy spring day, like so many others in my homeland. It ended in dread and mourning.

Of course, none of us knew the precise moment when catastrophe struck at Chernobyl 25 years ago. Back then, we lived under a system that denied ordinary people any right whatsoever to know about even essential facts and events. So we were kept in the dark about the radiation leaking from the shattered reactor at Chernobyl — and blowing in the winds over northern Europe.

But the more bizarre fact about the Chernobyl disaster, we now know, is that Mikhail Gorbachev, general secretary of the Communist Party of the Soviet Union, was also kept in the dark about the magnitude of the disaster.