Iran simply cannot trust such a major political bargaining chip to its so called partners (some of whom have shown that they are not particularly reliable). However, Irans counter offer to exchange on their soil is a major and significant step forward - a very positive development. Iran has actually agreed to cooperate with the West - albeit on terms more favourable to them (and who can blame them - any country would want to obtain the best deal for themselves). I hope that the world powers can now see that Iran does not pose a threat, and through good old fashioned negotiation an agreement can be reached. This may however not be the answer some countries wanted, but it should be enough to end all the talk of sanctions and 'other options'.