He is expected to press Israel not to carry out its threat to attack Iran's nuclear facilities.

VOA: standard.2009.07.26

Today's nuclear threat differs from that of the Cold War, according to U.S.Secretary of State Hillary Clinton, "The threat of nuclear war, nuclear attack that we grew up with in the Cold War has diminished.

VOA: standard.2010.04.11

For a country as small as Israel, even a small-scale nuclear attack could be an existential threat.

ECONOMIST: Conflict in the Middle East

During the Cold War, when the United States faced the threat of a nuclear attack, U.S. administrations made clear that any strike would prompt an all-out retaliation.

NPR: Cyberattack: U.S. Unready For Future Face Of War

And the weaker party, if nuclear capable, invariably holds out the threat of nuclear war as a way to deter conventional attack.

CNN: The Terrible Logic of Nukes