The phenomenon of Groupthink

Based on ONE famous case such as the 2003 Invasion of Iraq, the 2008 Financial Crisis, the 2011 Fukushima Nuclear Disaster, the 2014 Soccer World Cup Semi-final Brazil (1) vs Germany (7), the 2016 Democratic Party and the Clinton campaign, the 2018 Boeing 737 Max, the handling of COVID-19, OR the storming of Capitol Hill specifying how the phenomenon of Groupthink may apply. (If you have links to sources please include).