On Dec. 7, 1941, Gaddis Smith ’54 got a red bicycle and pearl cap pistol.

He had just finished a joint birthday party for himself and his younger brother when reports of a bombing at Pearl Harbor came in. In the year that followed, he collected scrap metal and learned to recognize silhouettes of German and Japanese fighter planes.

But he was never really worried.

“We would win, there was absolutely no doubt about it,” Smith told an audience of about 20 students and older community members Wednesday night at a talk sponsored by the Yale College Student Union. “We were right.”

All that changed on Sept. 11, Smith said.

“Realism assumed international relations were rational, based on a cost-benefit analysis. The enemy wanted to win, but was risk averse — not suicidal.”

A recently retired professor of history renowned for his work on the history of Yale and 20th century America, Smith discussed his memories of Pearl Harbor and the terrorist attacks of Sept. 11. At the talk, entitled “Remembering Dec. 7 and Sept. 11 — Autobiographical Reflections of an Historian,” Smith talked about his sense of how these events changed foreign policy.

Smith described the shifts in the thinking about foreign relations on campus since the First World War, from one so supportive of entering World War I that students built an armory to one with deep divisions between isolationist and pro-intervention students on campus on the eve of World War II.

The talk shifted between the policy musings of a well-versed historian and a survivor of two of the most defining moments of American life.

Smith said he felt pessimistic after Sept. 11, in part because of the uncertainty about possible future attacks, and because the old paradigm of realism was shattered.

Audience members, about half of whom were old enough to remember Pearl Harbor, looked on intently, particularly when Smith recounted his personal reflections on the wars.

After a 30-minute introductory speech, which he read from a typed set of notes, Smith answered questions from audience members.

Many of the audience members asked policy-related questions. But Jerome Freedman ’45, who had been sitting in the second row, shared his own experiences.

“I was here as a freshman on Pearl Harbor day, and I was here two months ago,” Freedman said.

He had been auditing John Gaddis’ class on the Cold War.

“I found the recent one much more scary,” Freedman said. “Pearl Harbor was probably more provocative. There was a vulnerability. We didn’t know where the enemy was. In ’41, we knew.”

Smith also recounted more personal memories of Sept. 11, and the other personal memories they evoked.

He recalled the day in August 1945 when he had heard about the bombing of Hiroshima. He said he and his family rejoiced that the war was over. But that night he had a nightmare.

Smith said he dreamed of the view of Manhattan he had from his house and imagined seeing the city with an aura of flames.

“On Sept. 11 I thought of that house and its current inhabitants on that preternaturally clear day,” Smith added.