Okay, "enjoying a video" about a nuclear arms deal is somewhat a contradiction in terms, but sometimes you have to make something enjoyable to get people to watch. And while much of it is funny, the bulk of it is trying to make a serious point. (Agree with that point or not.)
The group making the video is anti-nuke group Global Zero, so you can probably figure out that their position is one of support. But mainly, it's the odd mixture of people they got to participate -- and get in the spirit of things -- that leaps out. At the center are, as you'd expect, your Hollywood Celebrities, Jack Black, Morgan Freeman and Natasha Lyonne of Orange is the New Black. Then, there the few...hmm, unlikelies.
(There's one celebrity I didn't recognize -- and the funny thing is that most news outlets didn't either. But I bothered to take the time to try to find out. Which is when I discovered that most news outlets did and therefore couldn't say who it was. They'd just describe the three main celebrities above, and add "and other celebrities." The other is just this one guy. He's actor Farshad Farahat, who's an Iranian-American and most notably was in the movie Argo.)