It seems as if the leadership of the regime in Tehran fails to understand the very basic nature of diplomacy and just how, since January of last year, its interactions with the United States have entered a new phase with a stark reality. That reality is that it can no longer go about its business as usual in spreading unrest and sedition without there being severe consequences — and in the words written by US President Donald Trump on Twitter, is should “never ever threaten” the US lest it “suffer consequences the likes of which few throughout history have ever suffered before”.

The strong rebuke from Trump came following a speech from his Iranian counterpart, Hassan Rouhani said: “We’re not fighting or at war with any country, but the enemies have to clearly understand that war with Iran will be the mother of all wars and likewise peace with Iran is the mother of all peace.”

What makes President Rouhani’s words all the more startling is that he has gone to great pains to portray himself as a moderate in that regime. Clearly, that’s not the case given the inherent threat and incendiary tone in his words.

If the regime in Tehran thinks that it has the ability to continue as it has done for years, by funding and aiding its militias in Lebanon and Syria, unsettling the elected government in Iraq, arming and training Al Houthi rebels in Yemen, threatening to close both the Bab Al Mandab and the Strait of Hormuz, by providing succour to terrorists in Bahrain and by generally spreading sedition across this region in pursuit of its megalomaniacal and sectarian agenda, it has not learnt the lesson of these past months either.

By withdrawing the US from the international agreement on Iran’s nuclear programme, Trump has made it clear Tehran will not be rewarded for its meddling ways, and the re-imposition of strict economic sanctions shows that the US is prepared to act.

If Rouhani believes that by talking tough with the US and threatening action, ordinary Iranians will somehow be diverted from the harsh realities of their economic life and redirect their anger from the regime to the US, it’s a poor and crude attempt at political deflection — and Iranians protesting against their government deserve more credit than that.

The regime in Tehran is now reaping the inevitable consequences of what it has sown elsewhere, but threatening the US is not a wise move. There is, as they say in the US, a new sheriff in town.