'It's not peace yet': Experts react after Trump declares Israel-Hamas war is over

While President Donald Trump has declared the Israel-Hamas war over, some Middle East experts say the process to end the two-year conflict is just beginning.

Monday's historic release of the remaining living Israeli hostages in Gaza and the simultaneous release of more than 1,900 Palestinian prisoners that had been held by Israel is just part of the first step of Trump's 20-point plan to bring peace to the region.

"After so many years of unceasing war and endless danger, today the skies are calm, the guns are silent, the sirens are still, and the sun rises on a Holy Land that is finally at peace, a land and a region that will live, God willing, in peace for all eternity," Trump said in a speech on Monday to the Israeli parliament.

Trump added, "This is not only the end of a war, this is the end of an age of terror and death and the beginning of the age of faith and hope and of God. It's the start of a grand concord of lasting harmony for Israel and all the nations of what will soon be a magnificent region."

While Israeli Prime Minister Benjamin Netanyahu has been hesitant to publicly say the war with Hamas was over, he said during a speech that preceded Trump's address that he is "committed to this peace."

"Mr. President, today we welcome you here to thank you for your pivotal leadership in putting forward a proposal that got the backing of almost the entire world, a proposal that brings all our hostages home, a proposal that ends the war by achieving all our objectives, a proposal that opens the door to a historic expansion of peace in our region and beyond our region," Netanyahu said.

"Mr. President, you are committed to this peace. I am committed to this peace and, together, Mr. President, we will achieve this peace," the prime minister said.

Following his visit to Israel, Trump flew to Sharm el-Sheikh, Egypt, for a peace summit he co-chaired with Egyptian President Abdel Fattah el-Sisi and where the official signing ceremony of his ceasefire proposal occurred Monday afternoon.

Opening the summit, el-Sisi praised Trump for brokering a peace deal that is beneficial to the entire region. He invited Trump to "join the peace lovers' leaders, leaders who advocate for peace in the world."

"At this historic milestone, where we are all together, [and] witnessed the reaching of this Sham el-Sheikh agreement on ending war in Gaza," el-Sisi said.

He went on to call the agreement "a glimpse of hope that such [a] deal ends an agonizing chapter in the history of mankind, and opens the door, ushering in a new era of peace and stability in the Middle East."

Experts said that despite the historic initial phases of the peace proposal being executed, the meeting in Egypt, which included more than 20 world leaders, is where difficult next steps begin.

Michael Ratney, the former U.S. Ambassador to Saudi Arabia under the Biden administration, said that while it's hard not to get caught up in the emotion of the celebrations over the hostage and prisoner releases, there is a long way to go before peace is achieved.

"I'd like to say it was peace. It's not peace yet," Ratney told ABC News on Monday. "There's a lot of work, and that includes many of the measures that are on that 20-point plan that the White House released."

Sources familiar with the negotiations told ABC News that agreements still need to be reached on some of the most difficult points of the plan. These include the total withdrawal of Israeli forces from the Gaza Strip, Hamas ceding control of Gaza, disarming and decommissioning the militant group, and turning Gaza's governance over to an international trusteeship overseen by the U.S. and Arab allies.

"I don’t know if it’s an obstacle, but certainly a challenge. And one of them right now is going to be the process under which Hamas is demilitarized and demobilized as a terrorist organization or as a militant organization," Javid Ali, a former senior director for counterterrorism at the National Security Council, told ABC News on Monday.

While flying to the Middle East overnight, Trump implied to reporters on Air Force One that Hamas has been given the green light to act as a Palestinian police force in Gaza "for a period of time."

"They are standing because they do want to stop the problems, and they've been open about it, and we gave them approval for a period of time," Trump said.

He added, "You have to understand they've lost probably 60,000 people. That's a lot of retribution. They've lost 60,000 people, and the ones that are living right now were, in many cases, very young when this all started, and we are having a watch that there's not going to be big crime, or some of the problems that you have when you have areas like this that have been literally demolished."

Ali said it's going to take a great deal of time before Hamas lays down its weapons as required in Trump's proposal.

"It's still not clear who is going to actually oversee that demobilization, demilitarization, whether it’s the Israel Defense Forces or this international security body that’s still not comprised and on the ground," Ali said.

Ali said there have been other examples throughout world history of rebel groups cooperating with peace accords after long periods of fighting. He noted that the Irish Republican Army did so in the late 1990s after a long struggle with the British government, and that the Revolutionary Armed Forces of Colombia, a guerrilla group also known as FARC, agreed to disarm in 2016 after signing a ceasefire accord with the Colombian government.

“You literally have to account for the fighters, the people who would take up arms for these organizations, ensure that they don’t have the weapons and the capabilities to conduct and further acts of terrorism or militant operations," Ali said.

An example of how fragile the ceasefire proposal is arose on Monday when the Hostage Families Forum accused Hamas of violating the deal when it released the remains of only 4 of the 28 hostages who perished in captivity.

"We expect Israel’s government and the mediators to take immediate action to rectify this grave injustice," the Hostage Families Forum said in a statement.

Andrew Miller, senior fellow for the Center for American Progress, told ABC News that there is no appetite among the international community for Israel to resume the war, especially now that all of the hostages have been released.

"We've already seen a swell of international opposition to Israel's operation," Miller said.

Mick Mulroy, ABC News' national security and defense analyst and a former deputy assistant secretary of defense for the Middle East, said the success of the ceasefire plan depends on both sides following through on their promises.

"The only way this plan is going to work is if both sides adhere to what they agreed to do," Mulroy said. "Any of them fall apart, and it could challenge the rest of the plan."

Trump, however, expressed optimism in his peace summit speech, telling the world leaders gathered in Egypt, "This took 3,000 years to get to this point. Can you believe it? And it's going to hold up too. It's going to hold up."