U.S. President Donald Trump on Monday said the U.S.-Iran cease-fire was on “life support.” In truth, the cease-fire has been hanging by a thread from the moment it began, with disagreements over whether Lebanon was included in the agreement threatening to derail the truce in its early days.

In the time since, the cease-fire has faced consistent challenges amid a stalemate over the Strait of Hormuz and lack of progress in negotiations to end the war. There have also been repeated exchanges of fire, including in the past week, and both sides have accused the other of violations. Even still, while the cease-fire might be limping along, neither Washington nor Tehran has moved to formally abandon it.

But the situation raises questions as to how a cease-fire is defined, who decides when a violation is committed, and what constitutes a complete breakdown. For insights on this, Foreign Policy spoke with Laurie Nathan, the director of the mediation program at the University of Notre Dame’s Kroc Institute for International Peace Studies. Nathan, an expert on cease-fires and peacemaking, was a member of the African Union mediation team for Sudan’s Darfur region from 2005 to 2006 and has served as a senior mediation advisor to the United Nations.

While cease-fire violations are as old as time, Nathan said “weak” mechanisms surrounding recent cease-fires “may be particular to Trump.”

“[Trump] is intent on transactional peacemaking that serves family and personal enrichment,” Nathan said, and the president’s “vacillation, almost on a daily basis and certainly on a weekly basis, makes the negotiations very difficult.”

This interview has been edited for length and clarity. 

Foreign Policy: Since a cease-fire was declared in the Iran war last month, there have been repeated exchanges of fire and a U.S. naval blockade on Iranian ports. A blockade is generally considered an act of war. Can we really call what has been going on between the United States and Iran over the past month or so a “cease-fire”?

Laurie Nathan: I’m going to make four points. The first is that cease-fires are never without violation. It’s almost inconceivable. Cease-fires are going to be violated to a greater or lesser extent and for a variety of reasons. All cease-fires are on a continuum. At the one end of the spectrum, the positive end, there are no violations or only minimal violations. At the opposite end of this spectrum, the violations reach the point where there is no longer a cease-fire—so you have a resumption of hostilities. Between those two poles, there’s a lot of space. The parties can be violating the cease-fire, although they still want a cease-fire and to avoid a full resumption of possibilities. It’s a continuum, not a binary.

Second point: Cease-fires are violated for different reasons. Sometimes, it’s inadvertent—it’s a mistake. Sometimes, it’s intended to gain a strategic or tactical advantage. Sometimes, a cease-fire is violated as a form of messaging with different target audiences, which is what I think is going on here with the United States and Iran. Maybe the target audience is the international community, your own domestic base, or your adversary. Maybe it’s your own hard-liners. So you violate a cease-fire in order to send a message, for example, to your hard-liners: “Guys, don’t worry, we’re not going soft. We’re still hanging tough.” Or you send a message accompanying a cease-fire violation to an adversary that you don’t mean to escalate radically—as Trump recently did, when he said it was just a “love tap.”

My third point is that the fewer cease-fire mechanisms associated with a particular cease-fire, the weaker it is and the less serious the parties are. That’s a general rule. The cease-fire mechanisms are monitors, a written text on the cease-fire that indicates what you can and can’t do, and a verification and dispute resolution mechanism. You can see some of that in the Trump plan for Gaza. But it’s very weak in the case of the United States and Iran—you don’t have a document covering the cease-fire. That’s always going to make a cease-fire vulnerable.

And my last point: When Trump is involved in peacemaking, whether it’s in the Middle East or in Africa or elsewhere, it’s difficult to interpret because there is a mixture of elements and motivations. Trump is apparently seeking a Nobel Peace Prize. He is intent on transactional peacemaking that serves family and personal enrichment. And [his negotiators are] just completely incompetent, utterly incompetent as negotiators or mediators. Often what one thinks is malice or agenda is actually just complete incompetence.

FP: Are we in a uniquely challenging era for cease-fires? Has the erosion of international humanitarian law and the rule of law more generally, or perhaps Trump’s transactional approach to peacemaking, made it more difficult to ensure the survival of cease-fires?

LN: There are certain new things, but what we’re seeing in respect to cease-fires is typical under any circumstances. If you look at the cease-fires for Darfur, which I was personally involved in as a member of the African Union mediation team, we had about 14. This is going back to the 2003-04 outbreak of rebellion in Darfur, and there were numerous violations of cease-fire agreements. Even in successful cases like the Comprehensive Peace Agreement for Sudan—which was in 2005, the North-South civil war, leading eventually to secession and independence of South Sudan—that cease-fire was violated countless times. That’s a positive example in the sense that the parties developed, strengthened their cease-fire mechanisms incrementally as they made progress in political negotiations, over a three-, four-year period.

Cease-fire violations have always been the case, and it’s not surprising. Parties involved in serious hostilities don’t trust each other, and they want to act first rather than react. They’re concerned about perfidious behavior by the adversary. It’s often the case that they’re violating cease-fires in order to strengthen their negotiating position. You very often have political negotiations coinciding with some kind of full or partial cease-fire.

So I don’t think we are really seeing new dynamics with cease-fires, with one exception. We’re seeing very weak attempts at cease-fires in terms of mechanisms, and that may be particular to Trump, rather than a sign of the times more generally. When the United Nations mediates a cease-fire, it’s very professional and very competent technically. Is the United States capable of doing a professional, technical cease-fire? Yes, of course. Just bring in the right military officers, and they could do it if they wanted to. But I don’t think Trump gives a shit.

FP: Who gets to decide when a cease-fire has been violated or collapsed?

LN: You could use a combination of objective considerations, including the number of violations and how serious they’ve been. A second set of subjective indicators would be: What’s the intent of the parties? You interpret the intent [of] the parties by their actions, not just by their rhetoric. But the third set of criteria would be: What are they saying? What is the rhetoric? Are they signaling full resumption of hostilities, or are they signaling that they don’t want escalation?

In the case of the United States and Iran, both sides are signaling they don’t want escalation but they’re not ready for more radical or substantial deescalation. For different reasons, much of which have to do with domestic politics, they’re willing to play this out for the foreseeable future at a low level of hostilities. That’s not an accident. They are avoiding escalation because neither side believes that would be in its interests.

So, to come to your question of whether this is a cease-fire or not—this is a cease-fire. It’s a cease-fire that has achieved a prevention of escalation, has not achieved a full elimination of hostilities, and is violated constantly but still holding in relative terms—relative to full-scale resumption of hostilities.

FP: Is it better for there to be a more rigid set of rules surrounding cease-fires, or does keeping things flexible offer more room for mediation to succeed?

LN: I would go with the former. Based on my own experience, a cease-fire entails the management of risk. When we’re designing a cease-fire, we know it’s going to get violated. And our job is to minimize the risk, to minimize the potential for violations—and when they do occur, to prevent violations from escalating to the point at which you no longer have a cease-fire. And therefore we are interested in the mechanisms that are mutually agreed to by the parties that tie their hands as tightly as they’re willing their hands to be tied.

And there’s a paradox. Neither side wants constraints on themselves, but they want their enemy to be constrained. And this is the challenge when you’re mediating cease-fire negotiations: To what extent can you tie the party’s hands to their collective satisfaction while not tying them so tightly that the parties feel the risk is too high?

In any cease-fire, you want to have monitors and an adjudication team. You want to have rules on what is a violation and what’s not a violation. If this were to be done competently—[in the case of] the United States and Iran—this is what you’d be doing. And Pakistan’s military has the capability to do this if the belligerent parties want it to.

FP: Iran and the United States participated in a round of talks in Islamabad but don’t appear to be inviting Pakistan to play that type of role to the fullest extent.

LN: That’s right. If Iran and the United States were to ask for mechanisms for the cease-fire, they would invite together technical teams from both parties and the mediator that would say, here are a basic set of rules, here’s what we’re doing about the Strait of Hormuz. All of that could signal to the public, and to each other, a level of seriousness about the cease-fire and commitment to the cease-fire that they don’t currently have. The level of distrust is too high, and both sides still think there are tactical gains from low-level hostilities. But if they wanted to strengthen the cease-fire, a mediator could play a really valuable role.

FP: To what extent can the impasse be blamed on the fractured state of Iran’s leadership at present?

LN: In this particular case, I think the problem lies more with the Trump administration. Trump’s vacillation, almost on a daily basis and certainly on a weekly basis, makes the negotiations very difficult.

I don’t buy the argument that it’s hard to negotiate with the Iranians at the moment because they’re divided. I don’t see the evidence of that. I would hate to be negotiating with Trump. The United States has walked away from several negotiations and deals with Iran. If you were on the Iranian side, it’s fair enough if you don’t trust your enemy as a negotiating actor.

FP: What is most important to understand about the factors that contribute to the success of a cease-fire and the surrounding mediation process?

LN: I’m a mediator. I pay attention to the technicalities of a cease-fire. But at the end of the day—whether conflict parties go to war, stop the war, sign cease-fires, abide by the cease-fires, etc.—it doesn’t depend on the mediator; it depends on the parties. Do they want a cease-fire? If they do, they’ll get it. They’ll work it out. If one or both don’t, then you don’t have a cease-fire. In the current U.S.-Iran war, both sides want not a full cease-fire but a low-level exchange of hostilities without escalation. That’s what they want, and that’s what they’ve got. The bottom line is it’s up to the parties.