After these events, Andropov suffered from a "Hungarian complex", according to historian Christopher Andrew: "He had watched in horror from the windows of his embassy as officers of the hated Hungarian security service [the "Államvédelmi Hatóság or AVH]" were strung up from lampposts. Andropov remained haunted for the rest of his life by the speed with which an apparently all-powerful Communist one-party state had begun to topple. When other Communist regimes later seemed at risk – in Prague in 1968, in Kabul in 1979, in Warsaw in 1981, he was convinced that, as in Budapest in 1956, only armed force could ensure their survival".