Berlin • It's getting to be a common refrain each time a report surfaces of right-wing extremists in the ranks of Germany's police and military: It's an unfortunate but isolated case, it does not represent the whole branch and, of course, in the future everything will be closely monitored.

This response, articulated by ministers and heads of security agencies, seemed to work for a while. Debates about extremism within security forces were kept in check and rarely resulted in long-lasting changes.