Walter Cronkite stands as an object lesson of how even the most influential Americans can expect a pummelling if they dare speak truth to power. It revolved around what became known as the Tet Offensive of 1968 when the supposedly vanquished Viet Cong insurgents rose up to overrun towns and cities the length of South Vietnam. In Saigon the guerrillas briefly occupied the American embassy, a symbol of US power and prestige in Vietnam.
Eventually American military firepower prevailed and the Viet Cong were largely wiped out in fierce fighting. While that appeared to be a victory in the Pentagon's view, it prompted Hanoi to step up the war by sending in regiments of the conventional, North Vietnamese Army.
In the aftermath of Tet, Walter Cronkite travelled to South Vietnam to draw his own conclusions and filed an opinion piece that sent shockwaves throughout America. Cronkite said that, try as it might, America was not going to win. On mainstreet America public support for the war collapsed but it still took another five years for American troops to leave the country.
America was traumatized by the failure of its war in Vietnam. America wasn't defeated, it just couldn't win and so it failed. In the wake of that failure, American hawks and the country's now widely discredited military blamed every scapegoat they could finger and one of their favourites was Walter Cronkite. Few could have withstood that. Cronkite was one who could.