With the creation of the Department of Homeland Security, America has accepted a permanent, institutionalized state of siege on its own soil. But is this the correct strategy? These lectures examine four conflicts in history, asking how great nations have defended themselves against ruthless enemies, and drawing lessons for today. The Greeks, the Romans, the Americans during their Civil War and the Europeans prior to World War II, all demonstrated how a timid, defensive strategy can result in years of stalemate. Only a self-righteous offense led by an intelligent, audacious general can end the bloodshed. Only a proper attitude toward warfare, toward an enemy and toward one's cause can enable the clear-headed military action needed to win a war of self-defense and protect freedom and peace. There is a deep connection between intellectual clarity, moral certainty, intelligent leadership and the offensive strategy needed to defeat a ruthless enemy.