As polarizing he might be, Sean Penn is no stranger to humanitarian efforts and crusading around the globe, as detailed in the documentary "Citizen Penn." Penn was in Ukraine when Russian bombs started falling in February 2022, which turns "Superpower" into a powerful chronicle of Ukrainian courage and resistance, in a way that reflects Penn's passion as opposed to journalistic detachment.

Although Penn happened to be in the right (or wrong) place when he was scheduled to meet with Ukrainian President Volodymyr Zelensky, "Superpower," which Penn directed with Aaron Kaufman, is the product of seven trips to and from Ukraine. That began in late 2021, when the prospect of a Russian invasion remained just an uneasy threat, and Penn was intrigued about telling the tale of the comedian/actor turned real-life politician charged with leading his country after playing one on TV.

Penn begins by addressing the nagging questions about his involvement in such matters to people prone to ask, as he puts it, "Who do you think you are, Walter Cronkite?," noting that his celebrity gives him the opportunity to travel around the world, and "Sometimes, I feel I can be helpful."

As his experience in Haiti makes clear, Penn is no dilettante when it comes to taking risks and getting his hands dirty, and he prepares for the task by going out to "listen to smart people," among them Steven Pifer, former US ambassador to Ukraine; Vitali Klitschko, the boxer turned mayor of Kyiv; and retired lieutenant colonel Alexander Vindman, former director for European Affairs for the United States National Security Council.

Those interviews bring useful historical context to the film before the shooting starts, including the 2014 protests, Russian annexation of Crimea and Ukraine's track record when it comes to oligarchs and corruption. His conversations with the Ukrainian people prove equally enlightening, both before the war -- when many expressed doubts about Zelensky -- and during it.

Penn also includes his efforts outside Ukraine, such as appearance on Sean Hannity's program after the war erupted despite his distrust of Fox News, noting that if Zelensky can exhibit such inspiring courage he can endure an interview to help publicize his cause.

Amid harrowing footage of Russian atrocities, Penn doesn't hide his admiration for the Ukrainian people's spirit and what amounts to envy of their unity, something that, as the wariness of his exchange with Hannity underscores, is sorely lacking in the US.

Although the title can be interpreted different ways, Penn has embraced that his superpower is his celebrity, which enables him to help call attention to stories -- especially those transpiring beyond US borders -- that might struggle otherwise. (The problem of short attention spans for world crises gets addressed within the film, with clips of the Will Smith Oscar slap and Johnny Depp-Amber Heard trial to illustrate the point.)

Of course, there are those quick to deride or dismiss actors like Penn stepping off the soundstage and into such roles. Still, if you've read this far and might not have clicked on a review about another Ukraine documentary, guess what? He made you look.

"Superpower" premieres September 18 on Paramount+.