For weeks, Israel and Hamas had been locked in fruitless negotiations to extend the fragile cease-fire in the Gaza Strip and exchange more Israeli hostages for Palestinian prisoners.

The talks stalled because Hamas refused to release significant numbers of hostages unless Israel promised to permanently end the war — a commitment Israel would not make unless Hamas agreed to give up power in Gaza.

Now, Israel appears to have returned to war in an attempt to crush Hamas’s hopes of retaining control of the territory.

Israel’s heavy aerial attacks on Gaza early on Tuesday stopped short of an immediate ground invasion. But they could develop into a full ground operation if Hamas refuses to give up control of Gaza, according to two Israeli military officials who spoke on the condition of anonymity in order to speak more freely.

Benjamin Netanyahu, the Israeli prime minister, has already reaped domestic rewards from the strikes. Hours after they began, a far-right party rejoined Mr. Netanyahu’s ruling coalition, bolstering the government’s fragile majority in Parliament, weeks after it left the alliance to protest the initial truce.

In Gaza, the strikes have served as a brutal reminder to Hamas of the destruction that it and Gaza’s civilian population face if the group doesn’t back down. The strikes killed hundreds, according to the Gazan Health Ministry, which does not distinguish between civilians and combatants, in one of the highest nightly tolls in months. Israel’s military also ordered residents in two Palestinian border villages to flee their homes, hinting at the possibility of an Israeli invasion there in the coming days.

Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.

Thank you for your patience while we verify access.

Already a subscriber? Log in.

Want all of The Times? Subscribe.