This week the UN is meeting on the Nuclear Non-Proliferation Treaty (NPT). The U.S. and the other four permanent members of the security council are supporting the call for a nuclear-free Middle East in an attempt to put pressure on Iran vis-a-vis its nuclear program.
Israel has held a policy of ambiguity towards its weapons program. It is not a member of the NPT and therefore is not in violation of any obligations. Iran is a member of the NPT and is considered to be "in violation" of the treaty by the United States. This situation is considered to be slightly hypocritical by other states, who see an NPT member which admits it has nuclear capabilities being treated with more scruticy than a non-NPT member which is ambiguous about its capabilities. Israel has said it would only consider becoming party to the treaty under an Israeli-Arab peace agreement, a position supported by the U.S.
Israel has a very fine line to walk between supporting efforts to condemn Iran's nuclear program and facing criticism for its own policies. But the restarting of peace talks coincides nicely with a number of prominent U.S. officials (Clinton, Biden, Obama) condemning Iran's nuclear program and advocating for a major Israeli security interest. Regardless of feelings towards Israel, the Obama administration has successfully created a coalition of states united against Iran. The conference is likely to put significant pressure on the Iranian regime internally, as frustration grows over increasing economic woes and isolation.
For Israel, it indicates that despite small political disagreements, the U.S. and Israel are very much aligned on matters of defense.