context to make up your mind with jim walsh, a research associate, security studies programme, and barbara slaven a senior fellow at the south asian center. jim walsh, let me start with you, we hear about breakout capacity as binyamin netanyahu calls it a vast nuclear programme. are these testable propositions can we know today, in march 2015 whether iran is pretty close to having nuclear weapons capability or not? >> i think you can. there's maths here if you do it you can figure it out. basically rain has to produce enough enriched material at 80-90% to make a bomb. they'd need so many centrifuges for so many hours a day and it is correct to say if iran does not allow an accumulation of the 5% material, they can't make a bomb. there's a lot of countries that have 3-5% enriched you uranium, but they can't make a bomb out of it. other countries like japan have enrichment or reprocessing that could in theory be used for a bomb. that's why we have the international atopic energy agency where inspectors go in and iran unprecedentedly go in daily and confirm that that is not happening. it's possible