JERUSALEM — After nearly a month of round-the-clock carnage and terror, Gaza and southern Israel experienced something new on Tuesday: calm.

Once an Egyptian-brokered cease-fire kicked in at 8 a.m., there were no rocket attacks or missile strikes. No tunnel infiltrations or shelled schools.

But there were no celebrations or declarations of victory, either. Just a single, haunting question: If this war is truly over, how long until the next one begins?

Both Israel and Hamas went into the fight seeking to change the underlying dynamics of a situation that has produced three rounds of combat in less than six years while crippling the Gazan economy. But after 29 days of fighting that claimed nearly 2,000 lives, it is far from clear that either side has.

That could mean the next round of battle kicks off in the coming few years, months or even days if both sides do not get enough of what they want during negotiations set to begin in Cairo on Wednesday.

Hamas leaders have repeatedly said they seek an opening of Gaza’s border crossings, the release of Palestinian prisoners and international assistance in rebuilding the territory’s shattered economy, among other demands. Israel wants a demilitarization of the strip and a promise of an end to the rocket fire.

Israel on Tuesday withdrew its remaining ground forces from Gaza just ahead of the 72-hour truce’s start time as both sides fired their final barrages.

An Israel Defense Forces spokesman, Lt. Col. Peter Lerner, said that Israel “would continue to maintain defensive positions from the air, from the coast and from the ground” just outside Gaza and that all would be prepared to return fire if the rocket strikes resume.

By Israel’s own admission, Hamas still has at least several thousand rockets despite firing 3,300 and losing an additional 3,000 to Israeli attacks. Hamas has reserved the right to dip deeper into its arsenal if Israel fails to yield to the group’s demands.

“They are still intact,” said Mkhaimer Abusaada, a political-science professor at al-Azhar University in Gaza, said of Hamas. “They are not broken. They did not wave a white flag. It’s still a very strong resistance organization.”