Carlson shared what appears to be a clip or announcement of Mearsheimer discussing Middle East topics. Mearsheimer has indeed publicly discussed genocide in Gaza and Israel's strategic setback with Iran in various interviews and talks. However, the specific claim about a potential nuclear strike in Europe cannot be confirmed from available sources. Without a direct link to the actual interview or event, readers cannot fully assess whether all three topics were covered together as Carlson framed them, or evaluate the full context of Mearsheimer's actual statements.