The more the US waits, the stronger its opponents become.  Preconditions delay engagement and negotiations. Sometimes it can take years before the parties even start talking to each other. In that time, Iran will continue to enrich uranium [1] and North Korea will continue to expand its nuclear arsenal [2] . If the US waits for preconditions to be agreed on and met, by the time president Obama gets to talk and negotiate directly with the leaders of these states, he will have a much bigger crisis to deal with. It may have even gotten to the point where diplomacy can no longer be used effectively.  [1] Borger, James. “Iran’s acceleration of its nuclear programme angers the west.” Guardian. 19 July 2011.   [2] Neuman, Doug. “North Korea expands nuclear relationships with outcast states.” Examiner. 11 May 2010.