“Letters From Baghdad” is a pseudo-documentary about the life of Gertrude Bell, a highly ranked British imperial political officer who was key to establishing the modern Iraqi state in the early 20th century. The film uses a combination of found footage from that time, Bell’s letters written to her family and interviews with Bell’s “contemporaries” who are the only actors cast in the film. The filmmakers (Sabine Krayenbüh, “Salinger” and Zeva Oelbaum, “Ahead of Time: The Extraordinary Journey of Ruth Gruber”) deftly weave together these elements to create a cohesive story about Bell’s life and character. She was an adventurous woman who scaled dozens of mountains, explored expansive deserts and traveled the world. But it’s hard to ignore the context in which she had these adventures — that of British colonialism. It’s not that “Letters to Baghdad” is an incompetently made or boring film. But it’s hard not to be overcome by the stunning historical blindness of the filmmakers.