There is no evidence that Iran has decided to build a nuclear weapon, and if it did, the U.S. and its allies would most likely be able to detect such a step soon after it was taken, CIA Director William Burns said Monday. As Israel weighs how it will retaliate against Iran after it came under an Iranian ballistic missile barrage last week, speculation has focused on whether it might choose to strike nuclear sites in Iran to try to cut off Tehran’s possible path to a nuclear weapon....