Nicolas Sarkozy's warning that "time is running out" to avoid western military intervention in Iran was largely aimed at Russia and China, which have refused to back tougher EU and US sanctions. But for Tehran, the French president's words will likely sound like a calculated, alarming escalation. How much longer, they may ask themselves, before we are attacked by the US or Israel or a combination, including the perfidious British and French? Why wait for the inevitable? Perhaps we should attack first?

This is how wars start, through a process of hostile rhetoric, mutual ignorance and chronic miscalculation. Anybody in Tehran following the impassioned US debate on Iran will be aware that an influential Washington constituency, aided and abetted by leading Republican presidential candidates Mitt Romney and Newt Gingrich, favours military action sooner rather than later. For these American hardliners, it is no longer merely a question of destroying Iran's suspected nuclear facilities. Regime change is the name of the game because, it is argued, that is the only way to ensure Iran never gets the bomb.

"A limited strike against nuclear facilities would not lead to regime change. But a broader operation might," argued Jamie M Fly and Gary Schmitt in Foreign Affairs. "It would not even need to be a ground invasion aimed at toppling the government. The US would basically need to expand its list of targets beyond the nuclear programme to key command and control elements of the Republican Guard and the intelligence ministry, and facilities associated with other key government officials. The goal would be to compromise severely the government's ability to control the Iranian population. This would require an extended campaign."

Luckily, this sort of horror-fantasy does not reflect Obama administration thinking – not yet, anyway. But while both sides' rhetoric could be dismissed as so much hot air, the infantile idea the Iranian nation would welcome US bombers and suddenly rise up as one to overthrow the theocratic regime reflects a more dangerous ignorance. This lack of mutual insight is not surprising given the estrangement that followed the 1979 revolution. But it needs to be recognised for the bear trap that it is.

When the White House sent a private message to Tehran last week about its so-called "red lines" in the Strait of Hormuz, the reaction was both puzzled and incredulous. "Out in the open they show their muscles but behind the curtains they plead to us to sit down and talk," said Ali Akbar Salehi, Iran's foreign minister.

Salehi should study American history – and what happens when red lines are ignored. Geoffrey Kemp of the German Marshall Fund in Washington noted: "Many Americans will recall that in 1964 a military encounter between North Vietnamese torpedo boats and the USS Maddox resulted in a pitched sea battle, which was enough to persuade Congress to pass the Gulf of Tonkin resolution that gave President Lyndon Johnson authority to begin the massive escalation in south-east Asia".

Patrick Clawson of the Washington Institute suggested Tehran's leadership appeared to think it could "win" a Tonkin-like sea war in the Gulf if it managed to sink a single American warship. This idea might be called the "Hezbollah paradigm", named after the 2006 Lebanon conflict, when Hezbollah claimed victory over Israel, despite suffering greater losses, simply because its forces had not been utterly destroyed.

"Iranian leaders might also decide the US and European strategy of escalating pressure leaves them with few options, in which case resistance may offer the best prospects. After all, when the US got its nose bloodied by the 1983 Beirut marine barracks bombing and the 1993 Somali 'Black Hawk down' incident, Washington withdrew its forces from both countries," Clawson said.

Iran's regime may also calculate that conflict with the US and/or Israel would serve its purposes by justifying a nuclear deterrent, by portraying them as valiant leaders of the global fight against Zionism and American imperial "global arrogance", and by rallying the nation (rather than dividing it) behind their defiant banner. These are frightening delusions, but all are part of the developing pseudo-reality of a war in the making.

Responding to the war drums in Washington, Robert Wright, writing in Atlantic Monthly, was at pains to show that regime change is no panacea. "You'd think that our eight-year adventure in Iraq would have raised doubts about the extent to which changed regimes will hew to our policy guidelines. There we deposed an authoritarian leader and painstakingly constructed a government, only to see the new regime (a) tell America to get the hell out of the country; and (b) cosy up to an American adversary (Iran!)."

This really happened, as did much else following the invasion of Iraq that could yet be disastrously replicated in Iran on a much larger scale. But as in 2002-03, the sense grows that decision makers and opinion leaders on both sides, caught up in their own false narratives, are not listening.