Administration officials disputed the suggestion that the staircase incident was part of a broader attempt to humiliate Mr. Obama. Instead, they said, it reflected how on edge the Chinese have been in hosting the Group of 20, a major summit meeting involving dozens of world leaders. The authorities largely emptied this city of 10 million before the meeting, paying the residents to take vacations. Hangzhou is a provincial capital, officials noted, so it does not have the experience of dealing with visiting V.I.P.s that Beijing or even Shanghai has. Read more