From 1975-2012, he appeared in many English language US and UK television and film productions. One of his early roles was Kaiser Wilhelm II in Michael York's adventure film The Riddle of the Sands. One of his most well-known roles was that of Dietrich in Raiders of the Lost Ark. Kahler's voice also appeared in video games including as Kaiser Vlad in Battalion Wars. Kahler played the Prince of Tübingen in Stanley Kubrick's 1975 film, Barry Lyndon. In 2001 he portrayed a Wehrmacht General in the World War II TV miniseries, Band of Brothers. In the 1982 Clint Eastwood spy thriller Firefox, he played KGB chairman Yuri Andropov, despite being young enough to be Andropov's son in real life.
The Scarlet Pimpernel of the Vatican was first broadcast in 2006 on BBC Radio4. He played Herbert Kappler. This was a drama by Robin Glendinning: a Nazi war Criminal is befriended by a Vatican priest in his cell, based on the real-life adventures of Monsignor Hugh O'Flaherty.
Kahler played the German Ambassador in the long-running "Ambassador's Reception" TV advertisement for Ferrero Rocher chocolate, uttering the line "Excellente!". He also appeared as a famous Germanic Architect in US television advertisements for the Kohler Company. In 2011 Kahler appeared as Dr. Hoffmanstahl in Sherlock Holmes: A Game of Shadows.
