Christian Ruhl joins the podcast to discuss US-China competition and the risk of war, official versus unofficial diplomacy, hotlines between countries, catastrophic biological risks, ultraviolet germicidal light, and ancient civilizational collapse. Find out more about Christian's work at https://www.founderspledge.com   Timestamps:  00:00 US-China competition and risk   18:01 The security dilemma   30:21 Official and unofficial diplomacy  39:53 Hotlines between countries   01:01:54 Preventing escalation after war   01:09:58 Catastrophic biological risks   01:20:42 Ultraviolet germicidal light  01:25:54 Ancient civilizational collapse