The wars in Eastern Europe and the Middle East shattered illusions. Russia’s unprovoked invasion of Ukraine, now in its twenty-first month, dispelled the notion that major land wars between European states were a thing of the past. Hamas' savage attack on Israel on Oct. 7, which was meant to provoke massive retaliation in the tiny Gaza strip, destroyed the idea that Israel’s strategy of deterrence could be sustained indefinitely. Moreover, both conflicts are offering hourly reminders that civilians pay the heaviest price when governments choose war instead of peace. In this episode, acclaimed military historian Andrew Roberts discusses his new book, co-written with Gen. David Petraeus, “Conflict: The Evolution of Warfare from 1945 to Ukraine.” Roberts applies his argument about the importance of strategic leadership to the conflicts in Ukraine, a mostly conventional war involving huge numbers of infantry, and Gaza, where the Israeli Defense Forces are facing a guerrilla army in a densely populated urban environment. Effective leadership is just as important today as when the Allies conquered Germany and Japan, whether wars are fought in jungles, deserts, packed city streets, or cyberspace. Russian president Vladimir Putin failed the leadership test in Ukraine. Israel is trying to destroy Hamas in Gaza. How should we define success?