There's a photo you've probably seen of Barack Obama and Anthony Bourdain hunched over a small table in Hanoi. Their sleeves are rolled up, their top buttons unbuttoned. The floor is speckled with dirt and a rusty fan blows air from a corner. Obama, a few months into his final year in office, is orating, and Bourdain is listening, really listening – he holds eye contact with the president and lets his shoulders relax.