Beyond the tactical maneuvering, what’s notable about Kerry’s posture is its clarity, force, and passion—not always the first qualities that spring to mind when you think of him. “What’s confounding about this debate is that it’s been cynically politicized by people who have simply wanted to exploit it, rather than find a real solution,” Kerry says. “The tragedy is that India, China, Brazil, and Mexico are racing to this marketplace and the United States is not; it’s a terrible indictment of where we are as a country in terms of dealing with big issues … But I’m not dissuaded or deterred. Because this issue isn’t going away. We have to deal with it.”

Kerry’s role on Afghanistan has been no less central or energized. Last fall, at the behest of Clinton and special envoy Richard Holbrooke, he engaged in a frantic and fruitful round of shuttle diplomacy, persuading Afghan president Hamid Karzai to hold a second-round runoff election in the wake of an earlier vote that was universally condemned as fraudulent to its core. That runoff, in turn, created at least a patina of legitimacy that allowed Obama to announce his new war strategy, with its temporary troop escalation, at West Point two months later…

Kerry has been among those expressing doubts. What’s been missing, though, is the sharpness or lucidity of his thundering on climate change. What we’ve seen from him instead is a more typically Kerryesque performance: well informed and well intentioned, but rife with ambivalence and equivocation. A few weeks ago, after making public a tranche of 40-year-old private discussions of the Foreign Relations Committee on Vietnam, he said, “Some of the parallels [with Afghanistan] are almost eerie.” But then Kerry reiterated his support for the current war: “But grim as the statistics are, heartbreaking as every death is, this is not the time to give up.”