(TNND) — President Donald Trump told reporters aboard Air Force One on Tuesday that the ceasefire between Israel and Iran is "very much in effect, and I think we're going to keep it there for a long time."

Not long before that, Trump fumed at both Israel and Iran for what he saw as violations of the ceasefire within hours of it being declared.

Israel attacked Tehran overnight, and Israel said Iran retaliated with missiles.

The tit for tat continued until Trump got Israeli Prime Minister Benjamin Netanyahu to stand down.

“I didn't like the fact that Israel unloaded right after we made the deal,” Trump told reporters Tuesday morning on the White House lawn before departing for the NATO summit in the Netherlands.

Trump expressed displeasure with both countries, telling reporters that Israel and Iran “have been fighting so long and so hard that they don't know what the f--- they're doing."

Later aboard Air Force One, after Trump talked with Netanyahu, the president struck a more optimistic tone about the ceasefire.

“I'd like to see everything calm down as quickly as possible,” Trump said, adding that Iran will not be allowed to have a nuclear weapon.

So, for now at least, the Middle East has a ceasefire between two powerful countries.

“It's very early on, so I think it's fair to describe it as fragile,” said Gordon Gray, a former ambassador who now teaches at the Elliott School of International Affairs at George Washington University.

“That being said, I think both sides have ... a great deal of incentive to honor it,” Gray said.

The Israelis accomplished most, if not all, of their military objectives in the 12-day war, Gray said.

The Israelis don't want to see further casualties among their people from Iranian air strikes.

And Gray said that Netanyahu has every reason to stay on the right side of Trump, who very much wants the ceasefire to hold.

The Iranians, Gray said, are reeling from the attacks, which included American bombers taking out several Iranian nuclear sites.

Iran’s military leadership has been decimated, Gray said.

Iran has suffered hundreds of civilian casualties from Israel’s strikes.

And Iran carried out only a "performative strike" against the U.S. base in Qatar so that it was “able to maintain at least a shred of face,” Gray said.

“And that should also allow them to honor the ceasefire,” added Gray, who was ambassador to Tunisia from 2009 until 2012 and had 35 years of government service.

Raphael Cohen, an expert in foreign policy, military strategy and the Middle East at RAND, described the ceasefire as “tense.”

The hope is that Iran is more willing to negotiate a permanent dismantlement of its nuclear program after it was hammered by warplanes for nearly two weeks.

Cohen said Iran wasn’t willing to agree to something on the level of the nuclear containment deal former President Barack Obama helped broker a decade ago. And Cohen said that wasn’t a deal Trump would’ve been happy to accept in the first place.

“If this doesn't lead to a deal, then you could easily imagine the ceasefire breaking down,” Cohen said.

Trump said Tuesday that he’s not looking for regime change in Iran or the “chaos” that transition would bring.

Both Gray and Cohen said the regime, led by Supreme Leader Ayatollah Ali Khamenei, could survive this turbulent period.

“Ultimately, this is on the Iranian people,” Cohen said.

The Iranian public is younger and more “western” than the Iranian leader, he said.

But rebellion is a risky proposition.

And he said a rally-around-the-flag effect could help prop up the Ayatollah at least for a time.

But the Ayatollah is 86 years old, and his death, even from natural causes, could be an inflection point for regime change in Iran.

Gray said Iran’s economy continues to suffer.

And he said the military strikes are likely to have eroded the legitimacy of the Iranian regime, which wasn’t particularly popular to begin with.

Could one of Iran’s terrorist proxy groups carry out an attack that jeopardizes the ceasefire?

Maybe, but those groups have been significantly weakened and may remain on the sidelines.

Gray said Lebanon-based Hezbollah has been left reeling from its fights with Israel, which decimated Hezbollah’s leadership.

“I think if they were going to do anything, they would have done it by now,” Gray said.

Hamas is also in no shape to help Iran.

Hamas sparked its own war with Israel when the terrorists attacked Israel on Oct. 7, 2023. Israel has pummeled Hamas in Gaza ever since.

The Houthis are a wildcard, Cohen said.

And Gray said he’s a little surprised the Houthis haven’t attacked Israel in support of Iran already.

But he noted that the Houthis recently struck a deal with the U.S. to end hostilities that began with the Yemeni rebels attacking ships in the Red Sea.

Cohen said Iraq militias could attack American bases there.

And he said he’s expecting Israel and Iran to return to the “shadow war” that has characterized their relations for so long even if the ceasefire holds.

Cohen said Iran was wise to only launch a “symbolic” retaliation against the U.S. with Monday’s missile attack on the Al Udeid Air Base in Qatar.

Iran gave advanced notice of the attack and calibrated the number of missiles it fired to the number of bombs dropped by U.S. planes on its nuclear sites, Gray said.

Cohen said it’s clear Iran wasn’t trying to kill American troops.

And he said the scope of the Iranian regime’s retaliation gives them an off-ramp in the conflict, both with Trump and with the Iranian public.

“Had they tried and succeeded in killing a large number of Americans, we would not be talking about a fragile ceasefire today,” Cohen said.