How would a war between Iran and the US unfold? If it so decided, the US could without doubt launch an attack that would devastate any Iranian military ambitions. It would take time to assemble the huge forces required but the wrecking of Iran’s military-industrial complex, targeting its nuclear, missile and drone programmes, could be completed in weeks. Beyond that are many uncertainties – and the UK could be drawn in, like it or not.

War with Iran would be very different from the 2003 Gulf war. Back then, a US-led coalition had control of the Persian Gulf and could marshal tens of thousands of troops in Kuwait and Saudi Arabia for the assault across the border into Iraq – a geographical advantage not available for an attack on Iran.

Saddam Hussein's regime was terminated more or less according to plan, but an immensely costly seven-year war followed. Even now, Iraq is deeply insecure and divided – and subject to considerable Iranian influence. Regime change in Iran itself could be more difficult still: last week I argued that, in the event of war with the US, Iranians would tend to unite rather than threaten the government. This is one reason why tens of thousands of US “boots on the ground” in Iran simply won’t happen, even if US super-hawks such as John Bolton and Mike Pompeo yearn for regime change.

Given the range of views in Washington, with these hawkish elements now counterbalanced by some more cautious voices, a deliberate attack on Iran seems less likely than a month ago, and this trend is boosted by some unexpected assessments from military analysts.

This is in marked contrast to the US going to war in Afghanistan after 9/11, when there were few dissenting voices in Washington. Even in the run-up to the Iraq war there was a reasonable unity of opinion, at least at first. An unusually significant example of the difference today is a double report in one of the main US military news outlets, Military Times: its journalists have talked to many serving and retired military about the conduct and likely path of a conflict as well as a number of academic analysts about the consequences of such a war.