Two weeks later, he married Julia Thorne, and on a trip to Europe with his new bride, Mr. Kerry, the 26-year-old ex-lieutenant took a taxicab from Paris to a suburban villa. The son of a diplomat, Mr. Kerry had managed to arrange a private meeting with North Vietnamese and Vietcong emissaries to the peace talks.
In the above context, here is what the NYT said in the wedding announcement published on May 24, 1970:
"Whether today's wedding becomes a similar footnote to history may depend on the bridegroom, a graduate of Yale and a veteran of the Vietnam war who is considering running for congress from his native Massachusetts.
"Mr. Kerry, who criticized the fundamentals of American foreign policy as class orator in the 1966 Yale graduation exercises, said he joined the Navy and went to Vietnam because he wanted to study that policy first hand.
"There he earned the Silver Star, the Bronze Star, the Combat Action Ribbon, and three Purple Hearts as the commander of a patrol boat on the rivers of the Mekong Delta.
"He recently discussed his conclusions over network television when he offered views opposing Herbert Klein, the Nixon Administration's director of communications, on the Dick Cavett Show."
Interesting that he went to Vietnam to "study that policy first hand"
From the very beginning, it appears he enlisted for his political aspirations and not out of a sense of patriotic duty or to win the war as the others who served during that difficult time. In other words, the war was a political opportunity for him.