Russian intelligence chiefs took part in secret meeting with U.S. officials . Outlined three potential flashpoints that could lead to all-out nuclear war . Said attempts to return Crimea to Ukraine will be dealt with as an invasion . Also demanded Nato breaks up so called 'rapid response force ' in the Baltics and stops arming those fighting pro-Russian separatists in Ukraine .
Russian intelligence chiefs took part in secret meeting with U.S. officials . Outlined three potential flashpoints that could lead to all-out nuclear war . Said attempts to return Crimea to Ukraine will be dealt with as an invasion . Also demanded Nato breaks up so called 'rapid response force ' in the Baltic and stops arming those fighting pro-Russian separatists in Ukraine .