As the series of cease-fires in honor of Christmas and Tet, the Vietnamese lunar New Year, got under way in the last days of 1967, Ambassador Ellsworth Bunker threw a New Year's Eve party, inviting everyone to come “see the light at the end of the tunnel.” That light turned out to be fire in the hole. On the evening of January 31, 1968, Americans turned on their television sets to view the nightly news. They had become somewhat inured to film clips depicting American combat teams combing the countryside for the ever-elusive enemy and Vietcong rockets exploding among supposedly secure villages and troop compounds. But the war had seemed to be going better during the winter of 1967-8, and amid optimistic prognostications by Westmoreland and others, hope that the long nightmare might soon be over began to rise in the collective bosom. What the nation saw that January evening withered that hope and blasted any chance Lyndon Johnson had of maintaining his much-coveted consensus.

The previous night, nearly seventy thousand communist soldiers had launched a surprise offensive of extraordinary intensity and astonishing scope. Violating a truce that they themselves had pledged to observe during the Tet season, they surged into more than a hundred cities and towns, including Saigon, audaciously shifting the war for the first time from its rural setting to a new arena – South Vietnam's supposedly impregnable urban areas. “War Hits Saigon” screamed the front-page headline of Washington's afternoon tabloid The News. But print accounts paled beside the television images.