After students have read on a controversial topic, such the cultural and societal foundations of war, divide the class in half to debate the issue: you have news another country is planning to attack yours, and now your committee must decide whether or not to go to war. Allow students to choose their own sides initially, pro or con, and then make adjustments as necessary: if one side has too many people, ask volunteers to switch sides. Then each team has a set time to prepare their case to present to other side. The other side will have the chance to argue against them and ask questions, so they must be prepared for that, too. A major rule is that each side must allow the other side to present before speaking.
This is valuable in teaching basic debate skills as well as team work and critical thinking/argumentation. Students may also learn some research skills as they will often get on the Internet to support their position.