Fears?

From The Times Online:

A claim by President Ahmadinejad that Iran has 3,000 working uranium-enriching centrifuges sent a tremor across the world yesterday amid fears that Israel would respond by bombing the country’s nuclear facilities.

Military sources in Washington said that the existence of such a large number could be a “tipping point”, triggering an Israeli air strike. The Pentagon is reluctant to take military action against Iran, but officials say that Israel is a “different matter”. Amid the international uproar, British MPs who were to have toured the nuclear facility were backing out of their Iran trip.

Even before President Ahmadinejad’s announcement, a US defence official told The Times yesterday: “Israel could do something when they get to around 3,000 working centrifuges. The Pentagon is minded to wait a little longer.” US experts say 3,000 machines running for long periods could make enough enriched uranium for an atomic bomb within a year.

Israel responded by serving notice that it would not tolerate a nuclear Iran. “Talks never did, and never will, stop rockets,” said Ehud Barak, the Defence Minister, after talks with the security cabinet.

The US and Western allies believe that Iran is using its civilian nuclear programme as a cover for weapon development. Tehran says that it merely wants to generate electricity.

The Times' headline for this story is:

US fears Israeli strike against Iran over latest nuclear claim

What I want to know is who exactly "fears" an Israeli strike against Iran? I'm hoping that they take the Iranian nuclear program out and that we help them.