Obama has three choices in this regard [i.e., to respond to the revelation of Iran's secret nuclear facility].
First, he can impose crippling sanctions against Iran. But that is possible only if the Russians cooperate. Moscow has the rolling stock and reserves to supply all of Iran's fuel needs if it so chooses, and Beijing can also remedy any Iranian fuel shortages. Both Russia and China have said they don't want sanctions; without them on board, sanctions are meaningless.
Second, Obama can take military action against Iran, something easier politically and diplomatically for the United States to do itself rather than rely on Israel.
By itself, Israel cannot achieve air superiority, suppress air defenses, attack the necessary number of sites and attempt to neutralize Iranian mine-laying and anti-ship capability all along the Persian Gulf.
Moreover, if Israel struck on its own and Iran responded by mining the Strait of Hormuz, the United States would be drawn into at least a naval war with Iran -- and probably would have to complete the Israeli airstrikes, too.
And third, Obama could choose to do nothing (or engage in sanctions that would be the equivalent of doing nothing). Washington could see future Iranian nuclear weapons as an acceptable risk.
But the Israelis don't, meaning they would likely trigger the second scenario. It is possible that the United States could try to compel Israel not to strike -- though it's not clear whether Israel would comply -- something that would leave Obama publicly accepting Iran's nuclear program.
And this, of course, would jeopardize Obama's credibility.
Source: Power Line