That's on the front page of the NYT right now. The link goes to an editorial:
Since becoming secretary of state more than three years ago, John Kerry has been a man on a mission — multiple missions, in fact — relentlessly traveling the globe.... [T]here has been something honorable, even heroic, about the persistence, hard work and faith in diplomacy....Work, work, work. Trying very, very hard. Relentlessly traveling the globe.... But even your friends call you naïve and unrealistic. And do you think maybe Vladimir Putin might take advantage of your earnest strenuousness and play a cynical game? Let me take several days to think about that, because I'm sure putting more effort into the enterprise will be laudable... honorable, even heroic... and I will deserve immense credit for working so damned hard.
Mr. Kerry sometimes displays a naïve belief in his ability to win people to his side if he keeps talking long enough....
To get the current cease-fire [in Syria], he warned Moscow that if the violence was not halted, Saudi Arabia and other Gulf states would send more weapons to the rebel groups. He insists he is not being unrealistic, although he knows from past experience that Russia could be playing a cynical game and that the cease-fire could fall apart. But you can hear the anguish when he says that this “may be the last chance we have to save a united Syria.” He deserves immense credit for trying.