In 1944, the State Security returned to Belgium with MI6 and the Dutch secret service, which was allowed to install itself in Brussels while waiting for the liberation of The Netherlands. The service would play a substantial part in the tracking and punishing of those who had collaborated with the Germans. Afterwards a severe political crisis ensued, as many Belgians opposed the return from captivity of the discredited Leopold III. The State Security had to monitor the opposing forces, especially the nascent communist movement. The onset of the Cold War shifted the focus almost entirely on communism. Soviet espionage would take priority when Belgium became the host nation of NATO headquarters. With British and American help, Belgian intelligence was significantly expanded to meet the surge of Warshaw Pact spies. As counterespionage took up a lot of time, from the 1970s onwards the spectre of international terrorism would come haunt Europe again. As a convenient transit country, Belgium would often feature in terrorist activity, which made the State Security play a key role in many counterterrorism successes. But starting in 1982, Belgium would itself fall victim to a surge of violence. The attacks by the communist terror group Cellulles Combattantes Communistes (CCC) coincided with a number of incidents committed by a band of gangsters (eventually acquiring the name of "Les tueurs du Brabant" or "Bende van Nijvel") which gradually intensified in the level of violence used. Whereas the CCC was rolled up within a year, the Brabant killers would continue their bloody activities before literally disappearing into the night in November 1985, after their most violent raid on a supermarket that claimed 28 fatalities. The case remains unsolved, the killers unidentified, to this day.