Sept. 11 is approaching, and American television is maintaining a polite distance. Since last year, when more than two dozen new documentaries and memorials were presented for the 10th anniversary of the 2001 attacks, our attention has receded again. Apparently the most appropriate gift for an 11th anniversary is reruns.

A close but not exhaustive survey of prime-time schedules through Tuesday turned up five new specials on the attacks, all on cable. New to America, that is — two are leftover inventory, having been shown in Britain last year. Why in Britain? Because all these TV documentaries about the most significant event in our recent history were made there, four by the same company, Testimony Films....