It started with an idea for a film about a funny bird: Volodymyr Zelenskyy, a comedian and actor who somehow got elected President of Ukraine. "This is going to be fun," said producer Billy Smith when pitching the idea to friend Sean Penn. Then things turned out differently. In the end, Penn, US director and actor, sits under a tree with Zelenskyj in Kiev in the summer of 2022 and ponders the war.

"Superpower" is the name of Penn's documentary, which had its world premiere at the Berlinale on Friday evening. It has become a portrait of Zelenskyj as the world knows him now. A 45-year-old man in a military green T-shirt who appears to have aged ten years in the space of a year. A man who seems to be there around the clock with appeals and requests for weapons and ammunition.

But the film is also like a real-time report of the days exactly a year ago, when everyone was guessing about Russia's plans and many believed what happened next was never possible. The film owes its relevance to an insane coincidence - that Penn was in Kiev on the day of the Russian invasion, or as he puts it, "at the center of the universe."

The director had been filming in Ukraine with his partner Aaron Kaufman for months before. He had spoken to activists of the so-called Euromaidan, the revolution of the winter of 2013/2014 that ultimately led to the flight of pro-Russian President Viktor Yanukovych and a break with Moscow. Had informed himself about the war that began in eastern Ukraine in 2014 and the annexation of Crimea.

But Selenskyj had promised the crew an interview for February 24, 2022 of all days. Penn didn't want to let that go, even though the deployment of Russian troops at the borders was becoming more and more threatening. Neither of them knew that the attack would start that day. Crazy enough, the interview actually took place. "It's great that you're here," says Selenskyj. This is also familiar in the meantime: the man seems tense, but concentrated and devoted. Then he hurries away again.

Don't expect too much in-depth information about the conflict from Penn's film. The creators openly admit that they were initially quite uninformed. "I don't think any of us really understood what Ukraine was," said co-director Kaufman after the premiere in Berlin.

"Then we spent a lot of time there and we fell in love with the people, we fell in love with the country, we also fell in love with this idealism," he continued. "After the last four or five years of American politics, we had lost touch with something they had: They have different views, different ways of life, but they all want to get better and they seemed very united."

That is perhaps the core of the film, this waking up of the two US directors to their subject. In the film, Penn repeatedly talks about how much the freedom of the entire West is being defended here. Penn is generally very present in his own work - he conducts the interviews, he comments. He can be seen traveling towards Poland in a minivan on the second day of the war. And how he returns to Kiev and to the front in the summer. Sean Penn in the trenches, that's also shown. A director who smokes a lot of cigarettes and always has a drink nearby, who is visibly shaken and battered by this war.

So this documentary seems like part of a mission that the Hollywood star, who has previously appeared as an activist, is currently pursuing: quickly more weapons for Ukraine, with the argument that dying can be stopped more quickly that way. He says of the Ukrainians: "They will win, the only question is at what price. The more you delay things, the more expensive it becomes."