Children in Ain al-Hilweh, the largest Palestinian refugee camp in Lebanon (Amazon Studios)

Am I my brother’s keeper? How you answer this question might determine how you feel about Chinese artist Ai Weiwei’s ambitious film on the world’s refugee crisis. If your answer is yes, the film has done its work, arousing empathy and a brotherly welcome for the masses yearning to be free. Less idealistic viewers may feel unease at the sheer number of arrivals and the vastness of what they need.

Ai stirred controversy in 2016 when he responded to the drowning death of the two-year-old refugee Aylan Kurdi by posing for photos on a Greek beach in the same position as the dead boy. Some called the gesture grief-porn grandstanding, but there is no question that the artist cares deeply about the world’s refugees. After all, he has undergone persecution by the Chinese government and been forced into exile himself.

Ai assembled 25 film crews to shoot refugee camps, ships, and movements in 22 nations, including war devastated Afghanistan and Syria, host nations Germany and Greece, and sealed borderlands like Hungary. The film captures the enormity of a grim statistic: 65 million people are on the move today, the largest number since the Second World War. And sometimes in this movie it feels like we meet or at least see every single one of them. The scope of Human Flow is epic but overwhelming.

The film unfolds loosely in impressionistic scenes. Refugees arrive on chilly coasts in packed, unseaworthy boats. They march in huge columns over woods and plains and cross the desert on trucks. Drone cameras zero in on huge resettlements camps in the dusty middle of nowhere and pick out overloaded vessels on stormy seas. Interacting with refugees, Ai makes a slightly awkward but sincere, comforting presence. Interviews with aid workers and migrants add a human dimension as statistics spell out dire figures on drought, famine, and conflict. Onscreen quotations from poets and philosophers add observations that are sometimes perceptive, otherwise vague and windy.

Human Flow’s sprawl helps drive home the cruel effects of war, climate change, poverty, and political repression on powerless people. It underscores the destructive role of the West in bringing turmoil to countries like Iraq. The documentary could well open hearts, wallets, and borders to the wretched of the earth. But a couple of issues stymie the film’s power. One is the number of locations. There are just too many. The film never concentrates on any place for long (except one—more about that in a minute), and they all start to feel the same.

Except they aren’t the same, and not all refugees are the same. Who should get priority of admission to another nation? Those fleeing war? Fleeing religious persecution? Looking for work? A boat arrives on the Italian coast jammed to the gunwales with able-bodied young men—men with the strength and daring to make a dangerous journey. There’s not one female on board. Should these hard-faced young guys have an advantage ahead of women and children because they successfully made the voyage?

Just as all refugees have their own story, host nations differ, too. Who can absorb migrants more handily, a big country like the United States or the struggling, isolated Republic of Macedonia? What level of acceptance can we expect from Italy, which doesn’t even have enough work for Italians to do considering its high unemployment rate? German chancellor Angela Merkel admitted more than a million immigrants to Germany in 2015 (at considerable political risk). How’s that actually working out? Whirling from Pakistan to Calais to the U.S./Mexico border, Human Flow skirts deeper investigation and meaningful distinctions. Perhaps it is unreasonable to ask Ai and his crew for answers to these questions.

The film commits a misjudgment, though, by constructing its lengthiest section around Palestine and Gaza. In a movie implying that human need rises above politics, this choice feels, well, political. Gazans are oppressed, and their situation looks dreadful, but it is also complex, highly polarizing, and long-standing—more than a million Palestinians have been registered living in refugee camps for more than 60 years. That in itself invites the question of how long a refugee situation can fester, given that the territory is largely dependent on foreign aid and a place where masked militias drive around at night armed to the teeth. Gaza could function as a warning Ai didn’t quite intend about the dangers of indefinitely harboring a traumatized refugee population with no solution to their problems in sight.

Human Flow runs on endless stories of human suffering and the expectation that viewers will be moved by them. Kind souls may greet the strangers at the door warmly. Other more cynical hearts will feel a twinge of skepticism, even trepidation.

Directed by Ai Weiwei
Released by Amazon Studios
Germany. 145 min. Rated PG-13