Why Iran Has Waited to Retaliate Against Israel for Hamas Leader’s Killing

Iran vowed revenge at the end of last month after a top Hamas leader was killed in Tehran, leading many in Israel to fear an imminent attack. Nearly two weeks have passed and no large-scale response has materialized, leaving Israel and the wider Middle East on edge.

The crisis comes at an especially delicate moment in Iran, which analysts say is trying to formulate a response that doesn’t let an assassination on its soil go unpunished, while avoiding an all-out war against a powerful adversary. It also comes as a new government in Tehran has taken office, which could be slowing a decision on how to respond.

Here’s a look at the crisis and the factors that could determine what happens next:

Why has Iran vowed revenge?

Iran and Hamas officials have promised to avenge the death of Ismail Haniyeh, a senior Hamas leader, who was killed in Tehran on July 31 after he attended the inauguration of Iran’s president, Masoud Pezeshkian. Iran, which backs Hamas, blamed Israel for the assassination. Israeli leaders have not said their forces were responsible.

A day earlier, Fuad Shukr, a senior commander in Hezbollah, which is also supported by Iran, was killed in an Israeli airstrike in a suburb of the Lebanese capital, Beirut. The Israeli government said that strike was in retaliation for a rocket fired from Lebanon that struck a soccer field in the Israeli-controlled Golan Heights, killing at least 12 people, mostly teenagers and children. Hezbollah has denied carrying out that attack.

But Mr. Haniyeh’s killing was seen as the greater blow to Tehran because it took place on Iranian soil. In response, Iran’s supreme leader, Ayatollah Ali Khamenei, issued an order for Iran to strike Israel directly, according to three Iranian officials briefed on the matter. Failing to follow through on that threat would suggest that Iran’s system of deterrence, built up over years and at great cost, was in fact hollow, analysts said.

Why hasn’t Iran responded yet?

A spokesman for Iran’s Foreign Ministry, Nasser Kanaani, said that “it is necessary to punish Israel,” echoing comments from other senior Iranian officials. But he also said that “Tehran is not interested in escalating the regional conflicts.”