Inadequate knowledge of all of Iran's nuclear facilities means neither Israel or U.S. could be sure they were able to destroy all targets in potential military strike
The story is very different, however, when it comes to destroying the full range of Iranian capabilities. There are no meaningful unclassified estimates of Iran's total mix of nuclear facilities, but known unclassified research, reactor, and centrifuge facilities number in the dozens. It became clear just this week that Iran managed to conceal the fact it was building a second underground facility for uranium enrichment near Qom, 100 miles southwest of Tehran, and that was designed to hold 3,000 centrifuges. Iran is developing at least four variants of its centrifuges, and the more recent designs have far more capacity than most of the ones installed at Natanz. This makes it easier to conceal chains of centrifuges in a number of small, dispersed facilities and move material from one facility to another. Iran's known centrifuge production facilities are scattered over large areas of Iran, and at least some are in Mashad in the far northeast of the country—far harder to reach than Arak, Bushehr and Natanz. Many of Iran's known facilities present the added problem that they are located among civilian facilities and peaceful nuclear-research activities—although Israel's precision-strike capabilities may well be good enough to allow it to limit damage to nearby civilian facilities. It is not clear that Israel can win this kind of "shell game." It is doubtful that even the U.S. knows all the potential targets, and even more doubtful that any outside power can know what each detected Iranian facility currently does—and the extent to which each can hold dispersed centrifuge facilities that Iran could use instead of Natanz to produce weapons-grade uranium. As for the other elements of Iran's nuclear programs, it has scattered throughout the country the technical and industrial facilities it could use to make the rest of fission nuclear weapons. The facilities can now be in too many places for an Israeli strike to destroy Iran's capabilities.