I recently updated the Author's Note at the end of The Losing Role to add a few more details about the actual undercover mission that inspired the fictional Max Kaspar's story. The real thing was about as desperate, and at times as farcical, as in the novel: 

The false flag special mission depicted in The Losing Role is based on an actual operation Hitler devised for his surprise Ardennes Offensive of late 1944 that launched the Battle of the Bulge. Under the code name Greif, German soldiers who could speak English were trained and equipped to impersonate American units behind the enemy lines, where they would wreak havoc and secure depots and bridges in support of the main offensive. The German offensive caught American troops resting in Belgium’s forested Ardennes region completely off guard, and in the bloody chaos the rumor spread that the American impersonators were crack enemy terrorists out to kidnap or kill US General Eisenhower, commander of the Allied Forces. The lore of German agents impersonating American soldiers reemerged in films, fiction and even history books as a frightening and deadly ploy carried out with skill and cunning. The commander, SS Lieutenant Colonel Otto Skorzeny (who has a brief cameo in The Losing Role), already had a daredevil’s reputation that didn’t temper the legend.

The reality was altogether different. The Germans hastily put together units of English-speaking soldiers using whatever troops and materiel they could gather. The men came from all branches of the German military and possibly included civilians. The ones who spoke English best had lived in America or Britain, but these numbered very few. Many of the English speakers had been sailors and naive students before conscription and were far from ideal soldiers let alone crack terrorists. One, Otto Struller, had been a professional ballet dancer, and it can be supposed that some had occupations such as waiter or writer. Some appear to have been misled about the mission, and couldn’t back out. At least one was shot for a breach of secrecy. The planning and training were slapdash, the mission desperate, its chances slim.

As part of Operation Greif, Skorzeny and his officers placed the better English speakers into a special commando unit, Einheit Stielau. They were sent out in captured American jeeps to infiltrate the American lines, and managed to confuse (already bewildered) American troops by switching signs, passing along bogus information and committing sabotage. The Americans captured some of the Stielau men and promptly shot them by firing squad, including Struller. As the main German offensive sputtered, Skorzeny called off Operation Greif and the false flag infiltrators fell back to join regular units. If anything, the commando mission helped the Americans, since the wild rumors about cutthroat Germans in GI uniform gunning for Eisenhower only served to keep American counterintelligence alert and strengthen the troops’ rattled resolve.

In 1947, the Allies’ Dachau Trials were to make an example of the infamous Skorzeny and his officers for running a villainous ruse that ran counter to the so-called rules of war, but the defense brought in Allied officers who had to admit they’d been running similar special missions all along. Skorzeny and all defendants were acquitted.

My research included solid sources in English and German, but I left details about military strategy, top leaders’ decisions and so forth to historians. My version of this story remains true to overall events, though I changed or invented some aspects for fiction’s sake. Max Kaspar is a fictitious character, after all, part of a fictional commando team that infiltrated American lines in a US jeep disguised as American soldiers. Whether in fiction or reality, surely not all the false flag infiltrators like Max were accounted for. One imagines a good smart one or two disappeared into the night and got as far away from war and tyranny as they dared. I attempted, with respect for the history and with some dark humor, to tell the story of one of these inspired and probably doomed dreamers.