Thursday Briefing

Professors in Tehran protesting the killing of Ismail Haniyeh.Credit…Arash Khamooshi for The New York Times

Iran and Hamas vow to strike back

The assassination yesterday of Ismail Haniyeh, a top Hamas leader, in Tehran has left the entire Middle East on edge, bringing vows of revenge from Iran’s leaders and threatening to derail fragile negotiations about a Gaza cease-fire.

Both Iran and Hamas accused Israel of killing Haniyeh, which Israel has neither confirmed nor denied. Now, the focus is on whether a response from Iran and its proxies could lead to a regional war. Iran’s supreme leader, Ayatollah Ali Khamenei, said Haniyeh’s assassination would prompt a “harsh punishment,” and officials said he had issued an order for Iran to strike Israel directly.

In recent years, Israel has carried out several high-profile assassinations in Iran, rattling the country’s leaders. In November, Prime Minister Benjamin Netanyahu of Israel told reporters that he had ordered the Mossad, Israel’s foreign intelligence service, to “act against the heads of Hamas, wherever they are.”

White House reaction: For President Biden, the back-to-back assassinations of a Hezbollah commander in Lebanon and the political leader of Hamas in Iran have once again scrambled the geopolitical equation and revised the risk assessment of a wider war in the Middle East.

In Israel: Riots broke out after Israeli soldiers were detained on suspicion of sexually abusing a Palestinian detainee, highlighting a growing divide among Israelis about the conduct of their soldiers.

Hamas: Haniyeh was among the most senior members of the leadership of the militant group. Who are the organization’s other prominent leaders?