A Kerry boomerang: "In the Senate four years — and that is the full extent of public life — no international experience, no military experience, you can imagine what the advertising is going to be next year," Mr. Kerry said. With a grin, he added: "When I came back from Vietnam in 1969 I don't know if John Edwards was out of diapers then. Well, I'm sure he was out of diapers." Mr. Edwards, who is 50, was two months short of his 16th birthday when Mr. Kerry returned from his tour of duty in Vietnam. Later Sunday evening, Mr. Edwards responded: "I honor his service in Vietnam. In 1969, I was sitting around a kitchen table with my parents trying to figure out how we would pay for college like so many Iowans do every single day. And that is a difference between me and Senator Kerry." Late Sunday night, Mr. Kerry called Mr. Edwards to apologize for the remark, Mr. Edwards's advisers said.