You don't tackle things like Iran, climate change, proliferation, BMD or cyber-threats on your own.

ECONOMIST: The future of NATO

Leaders attending the summit addressed a number of issues, including energy security, climate change and the situation in Iran, Afghanistan and North Korea.

BBC: Obama: Eurozone 'must focus on jobs and growth'

There are few diplomatic and economic challenges that can be addressed in the world without having China at the table: from North Korea, to Iran, to Syria, to global economic rebalancing and climate change.

WHITEHOUSE: The White House

The meeting also covered topics which the EU-US largely agree on - including worries about Iran's nuclear programme, efforts to increase clean energy technology and avoid climate change, as well as supporting democracy after the Arab Spring.

BBC: Eurozone crisis: Debt fears loom at White House summit

By coincidence, Mr Yazdi was arrested on the day that Iran's president, Muhammad Khatami, gave a press conference at which he promised to improve the political climate.

ECONOMIST: Iran