ROME — In December 1965, Cecilia Mangini joined her husband, Lino Del Fra, in North Vietnam to work on a movie about the war. Three months later, the United States-led bombing campaign got so bad that local officials ordered the couple to leave.

Determined to continue, they wrote a letter to the president of the communist state, Ho Chi Minh, asking to stay.

It is unclear whether he ever saw their plea, but in any case they left, reluctantly. She says the unfinished film remained “an open wound” for them.

“When I think that we could have made public what we saw,” she said, rather wistfully, on a recent January morning.