Manfred Gans caused consternation when he used his Bar Mitzvah speech in April 1935 in a small town in Germany to denounce the Nazis. He got away with it but in July 1938 his parents sent him to safety in England, where, however, he was interned as an “enemy alien” two years later.

It was not until July 1942 that he and other Jewish refugees from Germany, Austria, and Hungary were allowed to join the fight against Hitler as members of X Troop, an almost exclusively Jewish commando unit whose 87 members fought in France, Sicily, mainland Italy, Yugoslavia, Albania, Belgium, and the Netherlands.

When the war was over, some of them went hunting for Nazis in the rubble of Hitler’s Europe. Most of their parents had been murdered. But Manfred Gans had heard that his mother and father had been sent to the Theresienstadt camp in Czechoslovakia, although he did not know whether they were alive or dead.

As the world was celebrating VE day in May 1945, he got himself a jeep and a driver and drove 400 miles to find them. The Soviet guards were astounded when this British officer appeared at the gates of the camp. “I have come to find my parents,” he explained. They let him in…

One of his fellow commandos, whose father had been murdered in Dachau, went looking for his mother…

Their stories are told in X Troop – The Secret Jewish Commandos who helped defeat the Nazis written by Leah Garrett and published earlier this year. Some of the information about them is still classified, but Professor Garrett describes how they played a “crucial role” in the D-Day landings, in ridding the River Scheldt of German garrisons so that Allied shipping could get from the North Sea to Antwerp and so shorten vital supply lines, and in crossing the Rhine. “They killed, captured, and interrogated their way across occupied Europe and all their way into the heart of the Third Reich.”

One commando had himself escaped from Buchenwald after spending two years there and in Dachau. But many members of X Troop had come to England along with 10 000 other Jewish children on Kindertransport trains. Starting off as refugees, they and 55 000 other European Jews instantly joined other Germans in England as “enemy aliens” when war was declared. Many were detained in cruel conditions in England, Canada, and Australia, sometimes with pro-Nazi Germans. Itching to fight, they were eventually freed but allowed to do only manual work such as clearing up bomb damage.

In the middle of 1942, however, facing one German triumph after another, Winston Churchill accepted a proposal from Lord Louis Mountbatten, chief of combined operations, to establish a series of new commando units, one of which would be made up of German refugees – named by Churchill as X Troop.

During the war altogether 350 applicants were interviewed for X Troop. Only 87 made it through selection and training and qualified to wear the green beret of a British commando. One of those responsible for selecting X Troop said that their “hatred for Hitler had to be very much in evidence”. Asked why he wished to join a unit that undertook especially dangerous operations, one applicant said that his “father had been killed in a concentration camp”.

They had to be not only physically fit, but mentally agile too. They had to know more about the German army than most German soldiers knew. A key part of their job would be to interrogate Germans as soon as they captured them instead of sending them back down the lines to headquarters. Their own high intelligence and fluency in German would enable them to make immediate battlefield decisions.

The book contains numerous examples of how only a handful of members of X Troop captured surprised Germans by using flawless German to demand their surrender, and then extracting vital information.

“Good morning, gentlemen,” said one of the commandos to a German platoon he had captured off Sword beach on D-day. “Where is the path through the minefield?” The Germans were so startled to be addressed so politely in their own language that they pointed out the path through the mines.

X Troop never fought as a single unit. Its members were too valuable to be risked all at once. Instead, they were attached as individuals or in groups of two or three to other commando units in Normandy and other theatres.

They also had to assume new identities, including English-sounding names (so that Manfred Gans, for example, became “Fred Gray”). This was to help protect themselves in the event of capture. Since the British had refused to naturalise them, they faced execution as traitors to Germany or Austria. They also faced being shot on sight as commandos. And, of course, they faced murder as Jews.

Of the 45 X Troopers who landed in Normandy on D-Day, 27 were killed, wounded, or taken prisoner. Of the total of 87 men who served in the troop before it was disbanded in September 1945, 22 were seriously wounded and 22 killed in action. Others disappeared without trace. Eighteen were commissioned, four of them on the battlefield.

One of those who received a battlefield commission was Manfred Gans/Fred Gray. He had refused to return to England for officer training, as he did not want to delay his chances of going to find his parents.

Professor Garrett comments: “Most of [these men] were rooted in a Jewish intellectual tradition that prized ethical behaviour, and we see how this spilled over into their service. Rather than wreaking personal revenge on the Germans, they followed the rules of war. They coolly collected battlefield intelligence from the enemy and outwitted them using their intellect rather than brute force.

“As Manfred Gans, the efficient and steely warrior, would reflect after the war, he was most proud of getting literally thousands of Germans to surrender without anyone getting hurt.”

* John Kane-Berman is a policy fellow at the IRR, a think-tank that promotes political and economic freedom. Readers are invited to take a stand with the IRR by clicking here or sending an SMS with your name to 32823. Each SMS costs R1. Ts and Cs apply.