Because of the lack of intelligence we have no way of knowing if Iran already has a nuke(even a dirty bomb). What they need is a means to deliver it (ICBM). With this deal they can acquire the delivery system, even buy it. Israel is #1 on their list for destruction and the U S is #2. Without good information we are cutting our own throat. We have avoided nuclear war thus far because those who have nukes know what retaliation would come. Iran doesn't care. Once the NUKE door is opened it CANNOT BE CLOSED.