He formally joined the ADL in 1940, constructing the organization's legal department and civil rights program with his title as associate national directory.
[2] Forster retired from the ADL in 1979 and moved to private practice, working with the law firms Shea & Gould and Baer Marks & Upham.
Wall says Forster frequently visited Israel and his Labor Party leadership contacts, Yitzhak Rabin, Abba Eban and Teddy Kollek, and that Forster continued aggressive Israel advocacy and outreach after the rise of the Likud party in 1977.
Wall says Forster was a factor in the development of an ADL headquarters in Jerusalem in 1977 and an early proponent of hasbara, PR for Israel.
Wall says that, Forster continued practicing law after his retirement from the ADL, for instance representing Ariel Sharon in his successful 1983 libel suit against Time magazine.