Due to the long-range nature of bombing missions over occupied Europe, Allied bombers initially had no fighter escort to protect them from Luftwaffe fighters. They also had few options when they sustained heavy damage to their aircraft. Any loss of fuel, damage to engines or mechanical failure made the return trip to England or North Africa unlikely, if not impossible. Heading for neutral Switzerland or Sweden was often the only alternative to a German POW camp, a fate which no aircrew relished. This accounts for the 167 USAAF aircraft that intentionally landed in Swiss territory, and the many others that tried to do so unsuccessfully. During the war, German propagandists claimed that some aircrews intentionally flew to Switzerland with no damage in order to avoid combat. This rumor was investigated and debunked in April of 1944 by order of General Carl Spaatz, chief of US Strategic Air Forces in Europe. Nearly every USAAF aircraft in Switzerland was found to have received significant battle damage, and no charges were ever instigated against their crews.

Once in the custody of the Swiss government, American airmen were considered “internees.” Internees are treated almost identically to POWs under the laws of war, excepting that by definition an internee is held in a neutral state. Some other US soldiers entered Switzerland by foot, for which they earned the status of “evadee.” Evadees were not kept in camps, and could come and go as they pleased. Internees, on the other hand, were usually restricted to a specific area and kept under guard. The Swiss were determined to adhere strictly to the rules governing internees, largely because they were under constant threat of invasion by the German Army. Any hint of impartiality toward the Allies could have incurred dire consequences for a state that professed neutrality, particularly one surrounded completely by the Axis. USAAF personnel caught attempting escape were punished severely, sometimes well beyond the limits stipulated in the laws of war. The Swiss government’s policy toward neutrality was clearly illustrated by the fact that some USAAF bombers attempting to land in Switzerland were attacked by Swiss fighters and anti-aircraft weapons.

After landing in Switzerland, interned crewmembers were typically interrogated and then quarantined for a short period before movement to a permanent internment camp. The first permanent internment facility was established at Adelboden, and others soon followed in Wengen and Davos. Several “punishment” or concentration camps were also established to house internees undergoing disciplinary punishment, normally for attempting escape. These camps included Straflager Wauwilermoos, Hünenburg, Les Diablerets and Greppen. Wauwilermoos was the most notorious of the punishment camps, due to deplorable camp conditions and a fanatical Swiss Army commander. Incarceration in such facilities grew dramatically after the Allied invasion of France, mainly because of the increased prospect of escape to Allied lines.