Let’s conduct a simple experiment: search on Google for any image of a recent American President -- Johnson, Nixon, either father or son Bush, Clinton, Obama -- at the moment of their first election victory. Then, search again for an image of the same man a few years later. Each will show the fatigue that the White House brings, the weight of which the historian John Keegan once called “the Mask of Command.”

Lyndon B. Johnson, once he left Washington, let his hair grow out like the kids who, asking for peace in Vietnam, had ousted him. Nixon scared his friends with his pallor and then the night before his resignation, he threw himself on his knees to pray, with Henry Kissinger beside him. The wrinkles on George W. Bush’s face were more fine and intricate than a military map of Iraq. The ever-charming Bill Clinton went from grey to white and open-heart surgery after the Lewinsky scandal.

 These days, Barack Obama -- who has also seen his hair change color -- admits to feeling lonely in the capital; his daughters are growing up and “don’t have time” for him anymore. Even Obama is showing signs of stress, “tired” is what the Americans are calling it.

 He now knows what President Harry Truman meant - a man from a midwest farm, not a former university professor like Obama- when he observed: “If you want a friend in Washington, get a dog.” A classic photo taken by George Tames, taken on February 2 1961 is called “The loneliest job in the world...” It shows President John F. Kennedy, who had been sworn in a few days beforehand telling his fellow Americans to “ask what you can do for your country”, with his shoulders hunched, looking out the windows of the White House, overburdened with tension, in silence: alone. It looks like he’s asking himself what he could do for America, and his successor, Lyndon B. Johnson, would be photographed leaning on his table, listening to the list of those killed in Vietnam.

 Obama appears to be sturdy, as he sets to embark on this second term, facing down the budget showdown with Republicans and pushing ahead with new gun control measures after the school massacre in Newtown. The seemingly cold Obama confessed to the “loneliness” of the job, and it showed when for the first time in history, a President openly cried. He was emotional, of course. The truth is that despite having the most important job in the world, having miraculously pushed through health care reform, condemning Public Enemy No. 1 Osama Bin Laden to death, and getting re-elected against the odds...there is a grey zone where his energy seems to stop.  

 It’s a new Obama that we have seen since November, capable of emotions and of strength, in tears but cunning in beating the opposition over the “fiscal cliff.” But the price that he has paid is his loneliness. It is the fate of leading America, where the one with the greatest power is also the loneliest, as Spielberg illustrates in his new movie “Lincoln.”

 There was only one President who seemed to avoid this destiny: Ronald Reagan, who entered Washington smiling and left eight years later the same way. Maybe it was because he saw it as a temporary set of “political cinema”. In response to the Russian leader Mikhail Gorbachev, who had asked him “What should I see in Washington?” Reagan beamed back: “California.”