shelters serve as wine cellars and closets. Thousands of tunnels, highways, railroads, and bridges are built with tank traps and primed with demolition charges to be used against invading forces; often, the civilian engineer who designed the bridge plans the demolition as a military officer. Hidden guns are aimed to prevent enemy forces from attempting to rebuild. Permanent fortifications were established in the Alps, as bases from which to retake the fertile valleys after a potential invasion. They include underground air bases that are adjacent to normal runways; the aircraft, crew and supporting material are housed in the caverns. However, a significant part of these fortifications was dismantled between the 1980s and during the "Army 95" reformation. The most important fortifications are located at Saint-Maurice, Gotthard Pass area and Sargans. The fortification on the west side of the Rhône at Saint-Maurice has not been used by the army since the beginning of the 1990s. The east side (Savatan) is still in use. During the Cold War the military expected that any invasion would likely come from the northeast, as the Soviet Union associated the country with NATO despite its stated neutrality. The Swiss government thought that the aim of an invasion would be to control the economically important transport routes through the Swiss Alps, namely the Gotthard, the Simplon and Great St. Bernard passes, because Switzerland does not possess any significant natural resources. Peacekeeping overseas Operating from a neutral country, Switzerland's Armed Forces do not take part in armed conflicts in other countries. However, over the years, the Swiss Armed Forces have been part of several peacekeeping missions around the world. From 1996 to 2001, the Swiss Armed Forces were present in Bosnia and Herzegovina with headquarters in Sarajevo. Their mission, as part of the Swiss Peacekeeping Missions, was to provide logistic and medical support to the Organization for Security and Co-operation in Europe (OSCE), protection duties and humanitarian demining. The mission was named SHQSU, standing for Swiss Headquarters Support Unit to BiH. It was composed of 50 to 55 elite Swiss soldiers under contract for six to 12 months. None of the active soldiers were armed during the duration of the mission. The Swiss soldiers were recognised among the other armies present on the field by their distinctive yellow beret. The SHQSU is not the same as the more publicized Swisscoy, which is the Swiss Army Mission to Kosovo.