go on the open market and buy ballistic missiles buy conventional arms and they will have billions of dollars more to do so because their economy will be moving again thanks to lifting of the economic sanctions. you ll hear members of congress in both parties raise loud objections to this. the answer from the white house is we just struck a historic deal that pre-empted war with iran. this was the best chance to prevent iran from getting a nuclear weapon. this is a good deal. and john president obama is working on this from the very beginning of his presidency. reporter: yes, in fact if you remember back when running in the democratic primary in 2008 against hillary clinton, he said he would open negotiations with iran. he has done this. this is a major legacy moment for the president. this will be his signature in the national foreign policy achievement and warn they are very proud here at the white house. john karl thank you very much. we ll hear from you on gma and martha ra
a hurk key lean task where rebels might try to get the weapons. the mere act of turning them over and getting them under international control takes the weapons away from assad. you ve accomplished one of your major strategic objectives. no matter how long it takes? no matter how long it takes. reporter: no country that s joined the chemical weapons convention has ever used chemical weapons again. martha raddick, abc news, washington. the reason for john kerry going to geneva is obviously because they re trying to test how serious this proposal is. they want to talk about how it is going to get done. it is like you heard martha say, an incredible fete. it will take a long time, a lot of manpower. who s going to be involved? who s going to be in charge? and it s in the middle of a civil war. they have to verify and secure these lines in two to four years.