With the formal start of the second Bush administration only days away, an article in the latest New Yorker magazine suggests that Iran is now squarely in the US president's sights.
By Jonathan Marcus
BBC diplomatic correspondent
The piece by the veteran investigative journalist Seymour Hersh claims that US special forces have already been operating inside Iran.
Experts warn an attack might rally support around the Iranian regime
He also says that the administration's aims could include not just an attack on Iran's nuclear facilities, but full-scale regime change.
Hersh has made this kind of detailed investigative article on security matters very much his own.
Controversial he may be, and he is sometimes wrong. But often he has been proved spectacularly right.
He was one of the first to recognise the mistreatment of prisoners in Iraq as indicative of a wider problem that reached high into the upper reaches of the Pentagon.
Now he is warning that as the chaos in Iraq continues, Iran has become the Bush administration's next strategic target.
Hersh says US special forces have already been penetrating eastern Iran from Afghanistan in the search for underground installations.
Contingency plans for a full-scale invasion of the country are being updated, he adds.
The implication is clear: war clouds are gathering.
The problem is that in the world of intelligence, things are not always as they appear.
Given that the Central Intelligence Agency has largely been sidelined by the Pentagon, there may be many disgruntled CIA specialists who are more than happy to drop a word in Hersh's ear.
Equally, the complexity of any military operation against Iran's widely dispersed nuclear installations should not be underestimated.
This would not be like the single attack carried out by Israel against Iraq's Osirak reactor in 1981. Much of Iran's air defence system might have to be destroyed first.
And experts, cited in the article, note that far from precipitating the collapse of the Iranian regime, such an attack might rally support around it.
The most worrying part of Hersh's article is the fact that according to him, administration officials are discounting such warnings.
This might be a good moment for Hersh to be wrong - but it should be remembered that his track-record is an impressive one.