Why did Hamas attack Israel, and why now?

Israeli Prime Minister Benjamin Netanyahu declared his country is "at war" with Hamas after the militant group launched a massive terror attack from the Gaza Strip on Saturday, killing hundreds and prompting deadly rounds of retaliatory airstrikes on the Palestinian territory. The shocking escalation has left many people wondering why Hamas attacked, and why now.

Even before sweeping to power in Gaza in 2007, Hamas openly sought the "obliteration" of Israel as a matter of policy. Gaza, a narrow strip of land roughly twice the size of Washington D.C., has been sealed off since 2005 by both Israel and Egypt over fears of an attack, though smuggling tunnels have long left it notoriously porous.

With a population of 2.3 million people, Gaza is one of the most densely packed areas in the world. Because of the blockades, residents often call it the world's largest open-air prison.

Hamas has said it was motivated to launch the attack essentially as the culmination of long-building anger over Israeli policy, including recent outbreaks of violence at the Al-Aqsa Mosque in Jerusalem, but more generally over the treatment of Palestinians and the expansion of Israeli settlements. 

Israel and the U.S. have made it clear that both governments believe there's no "moral equivalence" to draw between Hamas' attacks on Israeli citizens — including the slaughter of families in their homes and hundreds of young people at a music festival — and the measures the Jewish state says it has had to take to defend itself from terrorism.

U.N. Secretary-General Antonio Guterres said that while he recognized "the legitimate grievances of the Palestinian people… nothing can justify these acts of terror and the killing, maiming and abduction of civilians."

The full reasoning behind the scale and timing of the attack launched Saturday, as with everything in Middle Eastern geopolitics, is unlikely to be straightforward, but below is a look at some of the underlying factors that likely contributed to Hamas' decision to lash out, despite the risk of drawing an overwhelming response from Israel.

Iran's ties with Hamas and the Palestinians

Iran has denied any role in Hamas' attack on Israel, but Hamas could not exist in its current form without Iran's financial and political support. 

Neither the Palestinian faction nor the Iranians have attempted to hide their close ties.

• What is Hamas? What to know about the group attacking Israel

If anything, plenty of evidence suggests the mutual respect and support between officials in Gaza and Tehran has deepened.

Hamas leaders, along with senior figures from other armed Palestinian factions such as Islamic Jihad and Lebanon-based Hezbollah, have visited Tehran multiple times in recent years, meeting not only with military commanders and politicians, but with Iran's Supreme Leader Ayatollah Ali Khamenei.

Iran and Israeli-Arab diplomacy

Many analysts and officials see Iranian fingerprints on Hamas' brutal assault, and they point to a flurry in diplomacy between Israel and some of its Muslim Arab neighbors — and Iran's self-interest in disrupting it — as a likely motive.

"This will almost certainly scuttle the prospects of any kind of rapprochement, for the time being, between Israel and Saudi Arabia," Stanford University professor Allen Weiner, who specializes in international conflict, told CBS San Francisco.

That diplomatic initiative had indeed been gaining steam, fueled by other new bilateral agreements in the volatile region — most notably Israel's first diplomatic breakthrough with a Gulf Arab state. Iran warned after what it called a "shameful" agreement between the Saudis and the United Arab Emirates was signed in 2020 that it portended a "dangerous future" for the UAE.

Just like its benefactors in Iran, "Hamas believes that the normalization of relations between Israel and the surrounding Arab states and the integration of Israel into the region is a significant threat, because those countries that do want to normalize with Israel have grown tired of surrendering their national interests to the Palestinian cause," Steven Cook, a senior fellow at the Council on Foreign Relations, told CBS News, adding that "it will be very difficult for those counties that have already normalized or are seeking to normalize, like Saudi Arabia, to move forward with Israel while it is engaged in these very significant military operations."

Cook noted, however, that it was "hard to imagine that this operation was planned specifically to undermine normalization."

Professor Ron Hassner, the Israel Studies chair at the University of California, Berkeley, told CBS San Francisco that Iran does have a lot to lose if two of its biggest regional adversaries manage to bridge their own decades-old divide, but he also doubted the diplomatic detente between Israel and its Arab neighbors was the primary motive behind the unprecedented Hamas attack.

It's more likely, he said, "a last-ditch effort by Hamas to appear and be noticed on the world stage."  

Hamas showing it's "a force to be reckoned with"

"I think the first thing Hamas wanted to do was remind the Israelis that they are there, and that they are a force to be reckoned with — a security force and a political force to be reckoned with," said Weiner, of Stanford University.

Cook, at the Council on Foreign Relations, told CBS News that Hamas' objective was "to not just relieve Palestinians of the occupation of the West Bank and Israel's blockade of the Gaza strip, but in fact strike at the heart of Israel."

Hamas has become a more potent symbol of armed resistance to Israel — arguably surpassing any other Palestinian faction — since it first proved its ability to strike inside the Jewish state during a 2016 flareup of violence. Many of Hamas' supporters around the world, and certainly in Gaza, will see the Saturday attack as a powerful assertion of that role, even as a victory.

"It does not matter whether we die or remain alive," a resident of the al-Shati refugee camp in Gaza told CBS News' Marwan al-Arghoul on Monday as she clutched her children close with the sound of Israeli airstrikes thundering nearby. "It's enough for me that our fighters humiliated the Israeli army. The videos coming from inside Israeli towns and Israeli army positions show how our sons are fighting bravely." 

Cook said Hamas understood its attack would almost certainly draw Israel into a war, likely including a ground operation, and he believes that may have been part of the plan.

Hamas trying to "draw Israel into the quagmire"

"I think that Hamas is counting on the fact that they will draw Israel into the quagmire, much like the quagmire that Israel experienced when it invaded Lebanon in 1982 and it took 20 years for them to get out," Cook told CBS News.

Hassner also thinks Hamas may have hoped to provoke Israel into a bloody retaliation.

The Palestinian militant group's "hope is that the Israelis will respond disproportionately, and will then be castigated by the rest of the world," he told CBS San Francisco, adding that from Israel's perspective, "it's very hard when the goal of your enemy is to maximize civilian casualties — you're fighting with a hand tied behind your back."

"Hamas has sometimes made the calculation that it is prepared to incur tremendous suffering within Gaza, and subject the people in Gaza to tremendous suffering, because that actually can have the effect of generating sympathy for the Palestinian cause internationally," said Weiner.

While many of Gaza's 2.3 million residents may not support Hamas, they are once again paying a heavy price in a conflict that has raged for decades.

For Hamas, there had "never been a better time"

As for the specific timing of the attack, Hamas may have been capitalizing on an Israeli government that was deeply distracted.

"They were focused on judicial overhaul — maybe judicial wrecking ball is a better term," former Israeli deputy national security adviser Chuck Freilich, now a senior fellow at Harvard's Belfer Center, told CBS News, referring to deeply controversial reforms Benjamin Netanyahu's far-right coalition government has pushed through.

The overhaul deeply divided the country, drawing tens of thousands of Israelis onto the streets in protest for several consecutive weekends earlier this year, with opponents calling it a loosely veiled bid by the executive branch to undermine Israel's democratic checks and balances.

"They were not focused on how to address the Hamas threat and Iran," Freilich said, specifically noting sharp resistance to the judicial reforms among Israel's former military officers and reservists. 

There were threats from multiple groups of Israeli reservists — hundreds of thousands of whom have been called up for duty in recent days — to refuse to attend regular training if the reforms were pushed through. 

Freilich said he and other analysts watched with dismay, predicting that Hamas could try to act while Netanyahu's government was essentially being forced to focus inward. 

"We saw the protests. We said at the time, if Hamas goes through with this, it will weaken the IDF, because people were saying people will not serve a government like this and, tragically, I saw it manifest in the worst possible way on Saturday."

Freilich said that amid Iran's recent high-level meetings with Palestinian militant groups, the Lebanon-based Hezbollah group explicitly said there had "never been a better time" to strike Israel, "so I imagine they decided to take advantage of it."

CBS News' Khaled Wassef in London contributed to this report.

In:
• War
• Iran
• Hamas
• Israel
• Gaza Strip
• Middle East
• Benjamin Neta​nyahu

Tucker Reals

Tucker Reals is the CBSNews.com foreign editor, based at the CBS News London bureau.