Sanctions and possible sabotage may be slowing Iran's nuclear drive, reducing the risk that Israel might resort to military strikes against the Islamic Republic's atomic sites any time soon. Technical glitches and other hurdles for Iran's uranium enrichment programme could also provide more time for diplomatic efforts by major powers to persuade it to curb work the West fears is aimed at making bombs, a charge Tehran denies.

Experts dissecting the computer worm suspected of being aimed at Iran’s nuclear program have determined that it was precisely calibrated in a way that could send nuclear centrifuges wildly out of control, lending credence to the theory that the worm was designed as an offensive counter-proliferation effort.

Stuxnet is the first worm of its type capable of attacking critical infrastructure like power stations and electricity grids: those in the know have been expecting it for years.

The Stuxnet worm is mutating and wreaking further havoc on computerised industrial equipment in Iran where about 30,000 IP addresses have already been infected.

The U.S. State Department last month warned of potential biological weapons programs in Iran, North Korea and Syria while asserting that major powers China and Russia have not provided full disclosures on their previous efforts on such armaments

According to an expert on the Middle East, Israel may soon no longer be alone in possessing nuclear weapons in that volatile region of the globe. But the other power with "the bomb" may not necessarily be Iran.

In what seemed intended as a display of technological advance, Iran said on Wednesday that it had fired a rocket into space carrying living organisms — a rat, two turtles and worms, according to the state-run Press TV.

Confidential intelligence documents obtained by The Times show that Iran is working on testing a key final component of a nuclear bomb. The notes, from Iran’s most sensitive military nuclear project, describe a four-year plan to test a neutron initiator, the component of a nuclear bomb that triggers an explosion.

The United States will test its core missile defenses for the first time in January against a simulated long-range Iranian attack, a top Pentagon official said on Monday, amid tensions with Tehran.

Long denied access to foreign technology because of sanctions, Iran has nevertheless learned how to make virtually every bolt and switch in a nuclear weapon, according to assessments by U.N. nuclear officials in internal documents, as well as Western and Middle Eastern intelligence analysts and weapons experts.