The opener: The debate began with a question on security intelligence. Martha Raddatz, the debate moderator, brought up the terrorist attack last month that killed US ambassador Chris Stevens in Benghazi, Libya. She asked; "Wasn't this a massive intelligence failure?"

Iran: A full-throated debate over threat of a nuclear Iran, in which Mr Ryan sparred with Mr Biden over Tehran's technological progress, was the first country-specific foreign policy talking point.

Medicare: Mr Biden and Mr Ryan also outlined their competing plans on the Medicare healthcare programme for over-65s, generating a debate on where exactly the cuts need to be made.

47 per cent: While Mr Obama did not mention Mr Romney's well know remarks that 47 per cent of Americans are 'dependant on Government' in the first presidential debate, Mr Biden took the opportunity in this debate to bring the comments forward. When discussing Mr Romney's economic policies, Mr Biden said, "It shouldn't be surprising for a guy who says 47 percent of the American people are unwilling to take responsibility of their own lives."

Economy: When asked about the economy and taxes, Mr Ryan said there aren't enough rich to tax to pay for all of Mr Obama's spending. Mr Biden said the only way to pay for Mr Romney's plan is to raise taxes for middle-class taxes, something the Obama administration does not want to do.