will be lifted all at once or quickly, or if it will be an incremental scaling back of the sanctions. the western powers would like some verifiable proof that iran is complying with any deal before lifting sanctions. iran would like them all taken back at the same time. other sticking points center around existing stockpiles. iran said over the weekend it is not in its plan to shift these existing stockpiles to russia. so what happens to those existing stockpiles? any kind of agreement now, though, would be a preliminary agreement that would form the basis of a more permanent deal at the end of the month of june. there is a lot of political capital invested here, the fact that participants are still talking mean there is is a will to come up with something. the question is, will they come