Watching how world leaders interact

Could there be a meeting this week, even an orchestrated public handshake between US President Obama and Iran's President Rouhani?

The two men are due to attend the UN General Assembly, and if it happens it will be the first time US and Iranian Presidents have met in 35 years.

Nancy Soderberg, a former American UN Ambassador, and Sherard Cowper-Coles, a former diplomat, discussed how world leaders behave towards each other.

"It's going to be fascinating to watch the dynamics between these two men," Ms Soderberg said.

"Remember that what you do say is just as important as what you don't say," Mr Cowper-Coles added.

First broadcast on BBC Radio 4's Today programme on Tuesday 24 September 2013.