hans blix is head of the former atomic energy agency, joins us from -- on skype from stockholm. what could that impact have on these negotiations? >> sanctions are a very important part of it but the u.s. sanctions ant the congress are only one part of it. there are sanctions imposed by the united nations security council, not as far reaching in terms of the economy and the european union decided to have also not any import of oil. so if there is a settlement now then i think for the iranians it's very important that the u.n. sanctions in the first play be lifted. because they see that as a sort of stigma as to placing them in a category of pariah in the world. >> dr. blix you know the prime minister of israel says you can't trust iran, so do members of congress and other leaders. how do you trust a country like iran? how do you verify that they're doing what they said they would do if there is an agreement? >> well, they have claimed all along that they have not been working to get a nuclear agreement, to get a nuclear weapon, and it's true that they have had a nuclear program