Trump lowers the bar for attacking Iran after its president insults him

In a Tuesday morning tweetstorm, President Donald Trump reversed his red line on attacking Iran — and seemed to undercut his own story about why he chose not to strike Iran after it downed a US military drone last week.

According to Trump’s own telling, he called off a planned missile strike on Iran last Thursday because he didn’t feel that potentially killing more than 100 Iranians over a destroyed unmanned drone was “proportionate.”

“We were cocked & loaded to retaliate last night on 3 different sights when I asked, how many will die. 150 people, sir, was the answer from a General. 10 minutes before the strike I stopped it,” Trump tweeted Friday morning. “[N]ot proportionate to shooting down an unmanned drone.”

Instead, Trump chose to launch a cyberattack on Iranian targets and placed further sanctions on Iranian officials, including Supreme Leader Ali Khamenei and his billions in personal assets.

Those moves led Iranian President Hassan Rouhani to fire back on Tuesday that the White House was “suffering from intellectual disability.”

Trump, of course, couldn’t just let that go — and responded with his own fiery tweetstorm against the Iranians.

But in the process of trying to look tough in the face of Iranian mockery, Trump actually reversed both his administration’s stance on dealing with Iran and his own position on proportionality.

The Trump administration has been extremely clear that its red line for attacking Iran is if the Islamic Republic kills an American.

Secretary of State Mike Pompeo had long signaled that the death of even one US service member would trigger a military counterattack by the US. Trump implied as much when he told reporters last week that “it would have made a big, big difference” to him had Iran killed troops instead of just downing a military drone.

But in his Tuesday tweets, Trump wrote, “Any attack by Iran on anything American will be met with great and overwhelming force.”

So Tehran doesn’t have to kill any Americans to trigger a US military response — it just has to target anything American — like, say, another US drone. That is a much lower threshold for military action, and thus greatly increases the chances that the US could strike Iran in the coming weeks or months.

The president’s tweet also seemed to signal a change in his views on a proportional response to an Iranian attack. Even if an American doesn’t die in an Iranian strike, he says the US will respond with “overwhelming force.” “In some areas,” he adds, “overwhelming will mean obliteration.”

It’s unclear exactly what that “overwhelming” response would look like in practice, but the word “obliteration” certainly suggests some Iranians would be killed in such a strike. Which means he apparently now thinks it’s acceptable to kill Iranians even if they haven’t killed any Americans first.

What’s particularly disturbing about Trump’s sudden reversal on that point is that it seems to have come about not as a result of some deep personal examination of the morality of such a response, but rather because Iran’s president made fun of him. The possibility that Trump’s willingness to kill Iranians is that easily swayed by superficial personal insults is terrifying.

It’s of course possible that Trump’s tweets are just bluster. He’s used this playbook in the past — remember “fire and fury” for North Korea? — and he may believe talking tough will get Iran to back down.

But history shows that’s not usually how Iran responds to being pressured. As Afshon Ostovar, an Iran expert at the Naval Postgraduate School, told me recently, Iran tends to lash out when backed into a corner.

Which means that Trump’s gambit could end in disaster.