As with most young Czechs, 31-year-old mathematician Petr Glivicky grew up with stories of the 1968 Soviet invasion of Czechoslovakia.

That event has a central place in Czech national memory and has left the country with a deep-seated mistrust of Russia. To this day, allegations of collaboration with Moscow aren’t taken lightly. But how can the Czech Republic, and other countries, respond to allegations of Russia’s political interference without over-reacting?

Glivicky’s experience offers a cautionary tale.

In 2007, when the United States announced plans to establish a radar base in the Czech Republic as part of a missile-defense shield, Glivicky, then a math student at Prague’s Charles University, joined hundreds of other campaigners against the installation.