It might be cruel. But policy is policy. What could we do?”

In One Child Nation, documentarian Nanfu Wang returns to her home village in rural China to investigate what it was like for Chinese citizens under the nation’s One Child policy, which lasted from the late 1970s through 2015. The policy dictated that Chinese citizens were allowed only one child, although it was later amended to state that couples who have a girl were allowed a second shot at having a boy after five years. It was a means of combating population growth — a “population war” that resulted in extraordinary cruelty and cultural trauma for generations of Chinese people.

Wang focuses on the impact of the One Child policy on the people who lived under it, using an ever-expanding ring of social connections to trace each subject’s story. She starts with her mother, aunts, uncles and grandfather, then fellow villagers, midwives and artists. She speaks to human traffickers and, finally, one of the American groups that helps investigate where adopted Chinese-American children really came from — because Chinese orphanages frequently doctor documents to make a profit selling unregistered children to Western couples.

It’s a deftly constructed documentary that feels intimate despite the scope and nature of tackling an public policy that continues to affect so many people. Wang’s work has a very clear viewpoint on the policy, coming from a woman who spent her upbringing in China only to later leave it to secure an education in the United States and become a filmmaker. She opens the movie explaining that the birth of her son raised questions about what her parents’ experience was like, giving birth first to a daughter and later being allowed to try for a son; her brother was born five years later.

Wang’s subjects are incredibly candid about their experiences and feelings. Most of them supported, and still support, the policy as it stood; with the mindset that it was public policy, what would they do? It’s a mindset that Wang has trouble understanding and thus explores, but the movie doesn’t spend time assigning blame or doling out punishment. Wang’s story is ethnographic in its empathy and narrative, capturing the complex experiences of her subjects.

One Child Nation is unsparing in its depiction of life under the One Child policy, graphically detailing the enforcement methods. Two midwives discuss their part in forced abortions or sterilizations … and infanticide. One has regrets and seeks redemption working as a nurse for infertile women trying to conceive while the other remains proud of her role in combating the population war.

Wang meets with an official in her own village who helped demolish the homes of those who had more than one child and who witnessed a forced sterilization: “Like I said, there were instances when women refused sterilization in a particular village, and then all the (male) county officials go and collectively force her to be sterilized. It was really fucked up! I couldn’t bear to watch. I couldn’t bear to take part in that. I just stood and watched.”

Throughout the documentary, Wang takes time to explore the related, continued nature of how central patriarchal descent is in a lot of traditional Chinese culture, and how this resulted in ways in which enforcement of the One Child policy heavily affected women. Even in her own life, Wang was forced to go work at an early age to help support her family so that her younger brother could study.

Many documentaries are comfortable acting as a call to action, but Wang does something more deft than that: She lets her subjects tell their stories. The One Child policy was replaced by a new Two Child policy. Wang documents the propaganda used for the 30-plus years of One Child and its impact on her family and fellow citizens, and how those signs and declarations have now been replaced by Two Child.

There’s never the sense that her aim is to change your heart, only to connect with it and let the conclusions flow naturally. Her self-confidence as a storyteller is tremendous and deserved. It’s hard to emerge from One Child Nation without sorrow for the profound losses, frustration at the terrible situations humans can put one another in, and empathy for everyone she interviews. It’s a tremendous work of documentary filmmaking.