In the opening days of his presidency, Donald Trump appears to be taking an unpredictable, albeit hawkish approach to foreign policy.

On Wednesday, his administration issued what seemed to be a threat to Iran. “As of today, we are officially putting Iran on notice,” his national security adviser Michael Flynn declared during a White House press conference after denouncing a recent Iranian missile test launch. On Thursday, Trump echoed that statement on Twitter, saying: “Iran has been formally PUT ON NOTICE for firing a ballistic missile.”

Trump, however, seems intent on sending the message that it’s time for the United States to take a harder line with world leaders. “When you hear about the tough phone calls I’m having, don’t worry about it,” the president said on Thursday. “We have to be tough. It’s time we’re going to be a little tough, folks. We’re taken advantage of by every nation in the word, virtually. It’s not going to happen anymore.”

 To get a sense of the potential consequences of Trump’s combative rhetoric, I spoke with Robert Jervis, a professor of international and public affairs at Columbia University and affiliate at the Saltzman Institute of War and Peace Studies. A transcript of our conversation, lightly edited for clarity and length, appears below.

Clare Foran: Let’s start with the Trump administration’s threat of putting Iran “on notice.” How much does threatening rhetoric matter, and does it matter more coming from a superpower like the United States?

Robert Jervis: It does matter. Think about how much of a price President Obama paid for saying there was a “red line” with respect to the Assad regime’s use of chemical weapons in Syria, and then failing to back that up with the use of military force. Now, I’m not arguing that Obama was unsuccessful. I think he actually was successful because the removal of chemical weapons from Syria ultimately went forward, which is what he wanted to achieve. But even so, there was a lot of harm done by his statement. People who served in his administration who also think the policy was a success admit they suffered around the world for the idea that he didn’t live up to his threat, not to mention suffering bipartisan attacks in the United States. If you make a threat and then appear to have backed away from it, there’s a price to be paid. Your threat is less likely to be believed next time.

Foran: What do you think might happen then if Iran decides to launch another ballistic missile test?

Jervis: So after Iran’s next missile test, and I’m willing to believe there will be a next test, it’s going to be tough. The question becomes what is Trump going to do?  It certainly could lead us down a path that does not end well. It could end with the United States isolated from our allies. It could end with the Trump administration backing down, and damaging its credibility, or it could end with the administration taking action that could eventually lead to military clashes with Iran.

Most likely, what the Trump administration might do is some kind of unilateral American economic sanctions that will upset our allies, not do enormous damage to the Iranian economy, and increase the chances that [current Iranian President] Rouhani will not be re-elected. That could be a big domino that could put the Iran nuclear deal in jeopardy.

Foran: What do you make of the reports that the Trump administration may be planning to impose sanctions on Iran as early as Friday in response to the missile test?

Jervis: Typically sanctions would be something that I would expect would be a retaliatory measure if Iran were to go ahead and conduct another test after the United States told them they were putting them “on notice.” It could be self-defeating to impose anything but very limited sanctions this quickly, because it suggests that the United States will retaliate no matter what Iran does. If that’s the case, then it’s not clear what incentive Iran would have to do what Trump wants. [For what it’s worth, the U.S. enacted sanctions targeting Iranian companies and individuals last January, which President Obama said were in response to Iranian missile testing.]

Foran: Trump has suggested that unpredictability can be advantageous in foreign policy since then our adversaries won’t know what we’re going to do. What do you think of that?

Jervis: It is true that there could be some cases where being unpredictable could be advantageous. It might create an incentive for countries to want to get out of his way because they may be afraid of what he is capable of. It’s possible that it could be a deterrent. I think the odds of this working, in the sense of getting Iran to give up missile tests, seem low, but it’s not impossible. They may decide to back off. There’s of course a slight chance that Mexico may be afraid of what Trump might do, and decide to pay for the wall, but I highly doubt it. Getting into a conflict with the U.S. would be very costly for other countries. We are the umpteen-pound gorilla in the room, and there’s enormous harm and good we can do. In most cases, if countries can stay on the right side of the United States, they will probably hope that they can do it.

But on the other hand, many countries have a strong sense of nationalism and will not want to give into the United States. Getting into a conflict with the U.S. could be damaging to a country, but it could be still be beneficial to a leader who decides to do it because it might allow them to be seen as heroic within their own country. Unpredictability and scaring people could also backfire for Trump if countries feel that they are going come into conflict with Trump no matter what.

When you look at the reports that Trump was combative with the Australian prime minister, well the prime minister might walk away from that and say, ‘Well, if he’s just going to be aggressive and belligerent from the outset of this relationship no matter what we do, then why should we try to do what he wants?’ Similarly, the Iranians could decide that even if they didn’t launch another missile test, Trump would just find another way to punish them. If punishment seems unavoidable, there’s no point in trying to appease.

Foran: What do you think is more risky: The potential that the Trump administration could damage relationships with countries that have historically been our adversaries, or countries that have historically been our allies?

Jervis: Trump has talked about the idea that our allies don’t carry their own weight, and that is absolutely true, they don’t. But alliances are still absolutely central to defending our interests. American power in the world is enormously enhanced by good relations with significant alliance partners, and the alliances underpin a lot of the world order that keeps us relatively safe and prosperous.

And you can’t disentangle our relationships with our allies from our relationships with our adversaries. If Trump, for example, pursues policies that most leaders around the world believe are imprudent with respect to a country like Iran, and that in turn alienates our allies, it could embolden our adversaries. If I’m an adversary of the United States and I’m confronted by America on its own, that is much less deterring than if I’m confronted by a strong alliance. For some countries, that dynamic might even create an incentive to provoke the United States. If our adversaries think they can provoke Trump into taking action that will alienate America’s allies, that could ultimately benefit them, especially if it ultimately breaks up our alliances.

Foran: What would you say to reassure someone who is concerned about the potential for escalating conflict under this administration?

Jervis: The permanent bureaucracy of the United States government can create a check on presidential recklessness, though the president can get us into situations you can’t easily get out of. It’s also important to keep in mind there are many kinds of conflict, and there are many intermediary steps before arriving at armed military conflict. There are a whole range of much smaller events or actions that might take place, and that are much easier to imagine than full scale war. At the same time, any kind of conflict can have a high cost in and of itself, and can lead to further escalation.

https://www.theatlantic.com/politics/archive/2017/02/trump-iran-sanctions-australia-mexico/515547/