A further laudable success involved the BND's activity during the Czech crisis in 1968; by then, the agency was led by the second president, Gerhard Wessel. With Pullach cryptography fully functioning, the BND predicted an invasion of Soviet and other Warsaw Pact troops into Czechoslovakia. CIA analysts on the other hand did not support the notion of "fraternal assistance" by the satellite states of Moscow; and US ambassador to the Soviet Union, Llewellyn Thompson, quite irritated, called the secret BND report he was given "a German fabrication". At 23:11 on 20 August 1968, BND radar operators first observed abnormal activity over Czech airspace. An agent on the ground in Prague called a BND out-station in Bavaria: "The Russians are coming." Warsaw Pact forces had moved as forecast.