The German Secret Service knew a lot more than hitherto assumed about the Swiss military defence system during the Second World War, according to the "Frontal" programme of the German TV station, ZDF.
But the secret information, potentially lethal to Switzerland's ability to defend itself never reached Hitler's circle, according to the programme makers. Instead it remained hidden, unused, in 100 boxes in the cellar of a castle in Austria, where it has only recently been made available to military historians and the "Frontal" journalists.
According to Udo Frank, the journalist who researched the documentary, broadcast on Tuesday, the uncovered material contains thousands of miniature photographs, ordinance maps, military orders and reports by secret agents operating in Switzerland.
In an article written and distributed to the media ahead of the broadcast, Frank concluded, "Each square metre of Swiss ground was covered systematically by German espionage."
According to Erich Schmidt-Eenboom of the Institute for Peace Policies in Weilheim (Bavaria), until now only expert who obtained access to the material a year ago, the head of the German secret service withheld the secret files from his superiors because he opposed a Wehrmacht attack on Switzerland.
Admiral Wilhelm Canaris, who was executed in 1944 for his involvement in the July 20 assassination attempt on Hitler, collected, protected and hid 20,000 documents covering the military situation in war-time Switzerland. The collection was later known as the Canaris archive and presumed lost.
The "Frontal" film quotes Canaris' former secretary, who is still alive, on how the risky concealment of documents was achieved by Canaris and a few close collaborators on his Austrian staff.
The Canaris archive was temporarily brought to Yugoslavia during the war. It remains in the possession of the family of one of the former Canaris associates who, according to Schmidt-Eenboom, wishes to remain anonymous. There are plans to sell the archive to whichever academic institution will offer the best price.
The Canaris archive is mainly notable for its size and the quality of the documents. Had they been passed on, Switzerland would have been "easy prey" to the Wehrmacht in the event of an attack, according to Schmidt-Eenboom.
"The sheer amount of information that the archive contains dwarfs everything that has been collected until now, for instance in Switzerland's federal archive in Berne," Schmidt-Eenboom said in an interview with swissinfo.
"As a military strategist, I could devise attack plans on the basis of the information provided which would leave an army like Switzerland's during the war completely exposed."
Swiss military historian Oswald Schwitter, who was also interviewed by the "Frontal" programme, says he was astonished to find and subsequently authenticate documents such as the detailed schedule for the construction, works and armaments plans which were made necessary by a re-inforcement in September 1940 of the Réduit, Switzerland's alpine bunker and defence system.
"Knowing such details could have made a difference," Schwitter said in an interview with swissinfo. But he disagrees with Schmidt-Eenboom, "It doesn't mean Switzerland would have been a walk-over for the Wehrmacht. Knowing about military sites doesn't mean you've cracked them."
Swiss historian Pierre Braunschweig, an author on Swiss-German secret service contacts during the war, told swissinfo the fact that the German secret service was well informed about the Swiss military situation had been well-documented before.
German agents had infiltrated Switzerland thoroughly, not least because thousands of Germans had lived and worked in Switzerland before the war and were well integrated into Swiss society.
The "Frontal" documentary is likely to trigger a renewed debate in Switzerland about whether the nation's untested alpine defence system of bunkers and artillery hold-outs was as invincible during the Second World War as was claimed by its strategic architects.
It could also revive debate about Admiral Canaris' role as a "secret friend of the Swiss," and about incidences of high treason among Switzerland's top military brass.
The idea that Admiral Canaris protected Switzerland from a Nazi invasion is not new. It is known, for instance, that the Reich's highest ranking spy delayed a report on an incident early in the war which could have embarrassed neutral Switzerland's General Henri Guisan and compromised the nation's war preparations.
After the German occupation of France in 1940, Wehrmacht troops had stumbled upon documents which proved that Guisan and the French high command had considered a joint military strategy against Germany before the start of the war. When the German propaganda officials wanted to exploit the incident, Canaris told them his report was "not ready."
However, the conclusion that Canaris was Switzerland's "saviour" was wrong, said Braunschweig. "Canaris' loyalty was above all to Germany as a nation, and he considered it in the German interest that Switzerland be maintained as a neutral country in which Germany could not only conduct vital financial transactions during the war, but which also allowed his secret service to maintain international contacts."
Switzerland might have been spared a German military invasion even if Canaris had passed his information on to Hitler and the military command, Braunschweig said. "By 1943 the thrust of war had moved beyond Switzerland. The country had become valuable to Germany for being neutral."
The Canaris archive find could lead to the discovery of unkown cases of high treason, military historian Schwitter thinks. And in cases of already convicted traitors, more may be known about what information they traded.
Schmidt-Eenboom quotes the case of a state secretary Dubois who was convicted of high treason after the war for leaking documents of the 2nd Army Corps to Germany. "Now a lot more will be made public," he said.
by Markus Haefliger