WASHINGTON -- What does one do about Sen. John McCain? Why can he not play the senior statesman? He is a veteran who endured more than anyone should endure during his imprisonment in North Vietnam. He is a Churchill scholar. He has been a distinguished senator, a worthy presidential aspirant and a powerful voice for many causes.
But he cannot help himself: the ill-considered statement is his trademark. Without knowing anything about the situation on the ground in Syria, McCain was foursquare for American intervention. Now he said that President Obama's handshake with Cuban President Raul Castro was akin to Neville Chamberlain's shaking hands with Adolf Hitler.
McCain knows much more about the events of 1938 than this cheap shot suggests -- I have heard him hold forth in front of the Churchill Society on the unfolding of the Third Reich's European strategy. So he knows better than to compare Obama's handshake with Castro to Chamberlain's grasp of Hitler's contaminated paw.
It is little understood these days in the United States how few options Chamberlain had, and how he owed it to the British people to forestall war until they were somewhat more ready to fight it. That is why Churchill joined the cabinet -- and why, at the time, he accepted Chamberlain's action.
But that is not the point. In his way, McCain's remark trashes the Mandela Doctrine, laid out in "Long Walk to Freedom," Mandela's 1995 autobiography: "If you want to make peace with your enemy, you have to work with your enemy. Then he becomes your partner."
Mandela's stature grew as his personal serenity and sense of high moral purpose began to be known not only outside of his prison on Robben Island, but also inside the prison as he began to affect his jailers.
Mandela was schooled by Methodist missionaries to persevere and to seek peace, to turn the other cheek. This was one part of his inner strength. The other came from his birth as a nobleman of his tribe; someone in line to be its king if the wider struggle had not been paramount.
From Mahatma Gandhi, who had led a civil rights campaign for ethnic Indians in South Africa in the first decade of the 20th century, from the missionaries and from his birth, Mandela knew who he was. He also had a selflessness. He could have been released from prison a decade earlier, if he had been prepared to renounce violence. He was not.
Unlike Gandhi, Mandela thought violence was a necessary tool in the struggle. Many otherwise good white South Africans thought he should have been put to death -- much in the same way we feel about terrorists today.
Yet when apartheid fell, not least thanks to Mandela's great partner in the making of the new South Africa, the former President F.W. de Klerk, Mandela insisted on peace and reconciliation, saving a troubled, beautiful land from more bloodshed.
Mandela shook the hands of his enemies, those who had imprisoned him for 27 long years. He shook their hands just as McCain has gone back to Vietnam and shook hands there.
In that atmosphere of celebrating the life a man who had the genius to shake the hands of those who wanted him dead, and then to have reconciled with them, it would have been a travesty of Mandela's legacy for Obama not to have shaken the bloodstained hand of Castro. That is what Mandela would have wanted and would have done himself.
It is probably what McCain would have done, too, had he won the presidency.
Llewellyn King is executive producer and host of "White House Chronicle" on PBS. Email, firstname.lastname@example.org.