The "Pre-bronze age war between two tribes in West Papua, 1963" video in the article is an embedded tweet. Twitter currently doesn't allow to view it without an account (extensively discussed on HN [0]). Fortunately, it is also available on Youtube [1] (longer version [2]).
[0] https://news.ycombinator.com/item?id=49694296
[1] https://www.youtube.com/watch?v=kNHIP2FJzko
[2] https://www.youtube.com/watch?v=JI4uirwxx1Y