Has David Cameron had his "45-minute" moment, after warning on Tuesday that Iran's nuclear programme was a threat beyond the Middle East?
Not quite. It is tempting to draw parallels with Tony Blair's warnings about the immediate danger of Saddam Hussein's weapons of mass destruction to the UK. Mr Cameron's comments to MPs on the Commons liaison committee were more measured, if no less chilling. It is stretching a point to suggest that we are being softened up for war with Iran. But it is certainly the case that the government is cranking up the rhetoric as it strengthens sanctions and diplomatic pressure on the Tehran regime.
The coalition is fast running out of patience with a regime it feels it simply cannot trust - "justified scepticism" is the diplomatic term for the UK position on Iranian reassurances.
No-one should be surprised that the position is hardening. When analysts look at the situation compared to a year ago, there are nothing but negatives to be drawn. What is the world supposed to make of a regime that continues to enrich uranium at levels well beyond what is needed for a civilian programme, hides its facilities deep underground and insists on giving the International Atomic Energy Authority the run-around when it attempts to inspect it?
The prospect of a nuclear arms race in the Middle East is a nightmare no-one wishes to contemplate. When you add this to concerns about the opaque nature of the political structures in Iran itself, its consistently belligerent approach to its neighbours and a woeful human rights record, it is no surprise that Iran remains at the very top of the list of the Prime Minister's priorities.
That is not the same as saying that the Cabinet is a nest of neo-cons determined to take us to war in Iran, or to back an Israeli strike. No-one in the British government wants another conflict in the Middle East.
Meanwhile, there is no doubt that the language from Benjamin Netanyahu, evoking the Allies' failure to act to stop the Holocaust, has not been helpful from a UK perspective. Although British diplomats understand the need for the Israeli Prime Minister to reassure his people, the problem, as several commentators have pointed out, is that Mr Netanyahu's language does not allow for any wriggle room. If Ahamadinejad is the equivalent of Hitler, and he is about to launch a Holocaust, then clearly there is a moral imperative to stop him.
The belief in UK government circles is that it is up to Iran to make the next move: to assure the world that its intentions are not genocidal.