"A nuclear-free world". That is what Barack Obama, the US president, has called for after Russia and the US signed a new disarmament treaty on Thursday that legally binds the two countries to cut the number of nuclear warheads by 30 per cent over the next seven years.

John Large, an independent nuclear consultant, spoke to Al Jazeera about the new pact. He analysed the positive and negative aspects of the treaty.

Source: Al Jazeera