The vast majority of the 1,517 American servicemen interned in Switzerland during WWII were US Army Air Force bomber crewmembers participating in the Strategic Air Offensive against the Axis. While the British employed nighttime area bombing, US B-17 and B-24 bombers targeted precision industrial sites during the day, concentrating on several key industries and finally focusing on the German transportation network. The US airmen who flew these bombers were young, and the doctrine they relied on was largely unproven due to the recent rise of long-range air power theory. Allied bombardment contributed to the downfall of the German war economy, but with a steep price. The USAAF lost 80,000 airmen, more than any other branch of the US armed forces.

Due to the long-range nature of bombing missions over occupied Europe, early 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 an Axis POW camp, a fate which no aircrew relished. This accounts for the 166 USAAF aircraft that intentionally crashed or 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 repeated by a U.S. consul in Sweden, who falsified a report that was delivered to the War Department. The rumor was investigated and debunked in mid 1944 by order of General Henry H. Arnold, commanding general of the USAAF. Nearly every USAAF aircraft in Switzerland and Sweden 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,” and were disarmed and interned for the remainder of the war in accordance with international law. Internees are now treated almost identically to POWs under the laws of war, although at that time they had only vague protections under the Hague Conventions of 1907, which did not explicitly provide safeguards other than minimum humanitarian protections. 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 internment facility for American airmen was established at Evilard in mid 1943. In November 1943 the airmen were moved to Adelboden, and other camps soon followed in Wengen and Davos after Adelboden quickly became overcrowded. Several “punishment” camps (straflagers) 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 pro-Nazi 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. The files of the internment commission recorded nearly 1,000 escape attempts by Americans starting in August of 1944.

Despite the severe treatment that some internees received at the hands of the Swiss government, the overwhelming majority of Swiss citizens were sympathetic to the Allied cause, particularly French Swiss who lived in western cantons. Many Swiss citizens risked punishment or exile by helping American airmen to escape the country. The posture of the Swiss government at the time was understandable in a historical context; Switzerland was not self-sufficient, and depended on foreign imports to survive. Neutral states were not required to restrict private citizens from selling munitions or equipment that contribute to the war effort of a belligerent nation, however, they could restrict commerce to one belligerent and allow it with another. By the passing of exclusive treaties, the Swiss government effectively restricted nearly all trade with the Allies, while at the same time providing loans, munitions and key industrial components for the Axis. This certainly violated their neutral status, although this decision probably preserved their political sovereignty and territorial integrity.