Intelligence officials in the U.S., Israel, and inspectors with the IAEA (International Atomic Energy Agency) in Iran agree that Iran is NOT enriching uranium to bomb-grade concentrations and does NOT have a nuclear weapons program under way.
These same officials agree that should Iran decide to enrich uranium above peace-time use concentrations, this would be exposed by inspections under way in a month or so, and it would take Iran a year to 18 months to actually build a nuclear weapon. There would be time then for decisions on an appropriate response.
Any attack on Iran could very likely spark a catastrophic regional war killing tens of thousands, cause world oil prices to skyrocket, drag the U.S. in, plunge the U.S. into more debt and wreck U.S. economic recovery.