Well quite - but it is what everyone else is also saying, ledhed included.
There is not sufficient evidence right now that Iran is developing nuclear weapons. However, there are many indicators that they are and inconsistancies with their version of events. They are uncooperative and bellicose - taking every opportunity to distance themselves from the outside world and the treaty they've signed. The NPT must be enforced - and "force" is a key part to that - and while there is no clear evidence that they've broken it yet, the UN, the IAEA, the EU and the US are becoming increasingly concerned - even the French are on board with sanctions, and they don't get decisive about anything. Maybe.
Waiting until they actually have the nukes is waiting too long - just the development of them is a breach of the NPT - and they already have delivery systems. So being prepared for war is the sensible thing to do:
"Qui desiderat pacem, praeparet bellum" - Vegetius.