World leaders started arriving in Washington yesterday for a showpiece summit at which Barack Obama will tackle the terrorist threat with a deal to secure all nuclear materials during the next four years.
Officials say this will be the biggest single issue meeting to take place in the US since the 1945 conference that set up the United Nations. But some diplomats add that the agenda is so constrained – and the results so preordained – that most of the business will be done in bilateral meetings, particularly today's between the US president and Hu Jintao, China's president.
The event, involving about 40 world leaders, is an example of Mr Obama's approach to international affairs and his emphasis on good relations with Russia and China. US officials say this approach is paying off, with last week's disarmament deal with Moscow, Beijing's moves towards renminbi appreciation and both countries' readiness to discuss sanctions on Iran.