If Live and Become strikes you as a vague title, the young protagonist of Radu Mihaileanu’s film would despairingly agree. His mother’s parting words before she sends him off in the 1984 Israeli airlift of Ethiopian Jews contain none of the specific instructions the boy needs, considering the complexity of his situation. For one, he isn’t actually Jewish—he’s a Christian Ethiopian masquerading as a Jew so he can live in Israel with the French family that adopts him. The child is, as a fellow Ethiopian expatriate tells him, “condemned to live,” and this courageous film plumbs the complications of being so wonderfully and terribly lucky. Renamed Schlomo (and played, at various points, by Moshe Agazai, Mosche Abebe, and Sirak M. Sabahat), he lands in a supportive if imperfect family, including a sugary mench of a mother (Yaël Abecassis) who licks his pimply face in a show of camaraderie when his school proves reluctant to welcome him as a pupil—one instance of how xenophobia stifles his assimilation. Meanwhile, Schlomo yearns for his real mother, purveyor of that impossible advice. If the film sometimes feels overwrought—and at once too long and too short—its subtle motifs and loud silences, as well as the enormity of its subject matter, keep us absorbed until the devastating end.