David Halberstam, the Pulitzer Prize-winning reporter, gives the opening lecture at "Vietnam and the Presidency", a national conference where leading historians, key policymakers of the Vietnam War era, and journalists who covered the war examine the antecedents of the war, presidential decision-making, media coverage, public opinion, lessons learned and the influence of the Vietnam experience on subsequent US foreign policy. The Vietnam War was the longest and most controversial war that the United States ever fought. It claimed the lives of more than 58,000 Americans and over three million Vietnamese. From the arrival of the first US military advisors in the 1950s to the fall of Saigon on April 30, 1975, US involvement in Viet Nam was central to the Cold War foreign policies of Presidents Eisenhower, Kennedy, Johnson, Nixon and Ford. The war has continued to affect the policies of subsequent presidents, and its legacy is particularly relevant today during America's war on terror.