Scientific collaboration during the cold war was one of the few links between the United States and the Soviet Union. It is sad and ironic that today's partnerships may now bear the brunt of US sanctions as a result of the situation in Ukraine (see Nature 508, 162; 2014).

Earlier this month, the FBI warned universities in Boston, Massachusetts, about venture-capital partnerships with Russia (see The US government is also severing scientific exchange by NASA and the Department of Energy with scientists in Russia. These moves are causing widespread consternation in the Russian research community.

Former Soviet and now Russian scientists have traditionally subscribed to democratic and pro-Western agendas (the nuclear physicist Andrei Sakharov is one famous example). Moreover, researchers, engineers and entrepreneurs of Russian origin have contributed significantly to the US enterprise. Indeed, after the collapse of the Soviet Union, the US government issued fast-track green cards to Russian scientists to retain their expertise.

By contrast, the new US policies are likely to be counterproductive. The presumption that Russian scientists are potential spies will force them to return to or stay in Russia, where research is in disarray because of sweeping reforms. Researchers whose projects are derailed are likely to blame the United States rather than Russia — a situation that could further damage relations.

There are signs that Russian scientists with foreign collaborators may come under more state control. It seems that both US and Russian bureaucrats lack understanding of the importance of international scientific collaborations and the way modern science works.