It’s not rare for conflict to erupt between Israel and Hamas combatants in Gaza. The usual pattern is as follows: Hamas launches projectiles over the Gaza border into Israel, the majority of which are intercepted by the Iron Dome — Israel’s highly advanced missile defense system. The consequences in Israel are generally mitigated.

Israel then responds with airstrikes on the densely populated Gaza Strip. But what happened last weekend was unprecedented in its scale and coordination. Militants attacked Israeli communication towers with improvised explosives, they breached the Gaza-Israel border fence within minutes and assumed control of several Israeli communities. They paraglided over the border and gunned down civilians at a music festival. Hamas killed at least 1,200 people in the attack and took dozens hostage, including women, children and the elderly — all while Israel’s military was late to respond. It was the deadliest attack Israel has seen in decades. Yesterday, reports confirmed that Hamas decapitated many infants and toddlers, however Hamas denies this accusation.

In retaliation, Israel has laid siege to Gaza with hundreds of airstrikes that have killed at least 1,000 Palestinians and displaced more than 200,000 people. It has cut off electricity, food and fuel supplies.

Speaking to mayors of the southern border towns that were hit by the attack, Israeli Prime Minister Benjamin Netanyahu said Israel’s response “will change the Middle East.”

Troops have now amassed for a possible ground invasion of Gaza, which last happened in 2014 and resulted in at least 2,000 Palestinians killed, and more than 70 on the Israeli side. It’s the biggest escalation in the decades-long conflict between Israelis and Palestinians in recent years.

But experts who follow the region closely point to key developments over the past year in Israel and the Palestinian territories that set the stage for this explosion of violence.

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.

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.

What was Hamas’ strategy in carrying out the attacks?

By undertaking such a devastating strike, the group’s primary goal would have been to dramatically shake up the status quo, experts say: Israel maintains a tight siege on Gaza and continues to occupy the West Bank, and the goal of an independent Palestinian state is nowhere in sight.

One objective would be to put the Palestinian issue back on the regional and international agenda, said Khaled Elgindy, a senior fellow at the Middle East Institute and director of its Program on Palestine and Israeli-Palestinian Affairs.

“People had moved on (from the Palestinian issue),” Elgindy told CNN. “The new game in town is Saudi-Israel normalization, and this new regional integration.”

Saudi Crown Prince Mohammed bin Salman last month publicly acknowledged for the first time that negotiations were underway with Washington to possibly establish ties with Israel, saying normalization is getting “closer” every day. Saudi-Israel normalization could be a landmark moment for Israel’s regional legitimacy as it might prompt other Muslim countries to follow suit. Saudi Arabia had previously pledged not to recognize Israel until it grants independence to the Palestinians.

Israel was distracted by political turmoil

Netanyahu was reelected less than a year ago and formed a government by aligning with ultranationalists and religious conservatives.

Tal Schneider, the political and diplomatic correspondent for The Times of Israel, told NPR that Netanyahu’s appointment of two controversial figures into his Cabinet intensified tensions within Israeli politics.

“He nominated someone who was convicted for eight times in inciting violence against Arabs,” Schneider said, referring to Itamar Ben-Gvir, the minister of national security. “This is someone who was outlawed, who was for us Israelis, someone who was not supposed to sit in government. Netanyahu made him a strong leader and someone who is fully engaged in politics.”

Ben-Gvir, along with Finance Minister Bezalel Smotrich, pushed for more settlements in the occupied West Bank, escalating tensions with Palestinians.

“The war Cabinet of Netanyahu was completely dysfunctional with them,” Schneider said.

Then there is Netanyahu’s plan to overhaul Israel’s judiciary, which has been delayed, but not abandoned, due to support from the far-right politicians, after mass protests broke out for months as Israelis rejected the proposal to weaken the country’s supreme court.

“They want to change Israel’s balance of power, the way Israel functions as a democracy. People here erupted, especially those who are doing reserve duty in the army. They went out to demonstrate and some of them announced that they will not serve anymore under a dictatorship. So, obviously, the military was very weakened,” Schneider said, adding that all of this contributed to Hamas perceiving a weaker 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.

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 Israelis 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.”

What is Hamas’ ideology?

Hamas is an acronym for Harakat al-Muqawama al-Islamiya, which means Islamic Resistance Movement, according to the U.S. National Counterterrorism Center. The group is “committed to armed resistance against Israel and the creation of an Islamic Palestinian state in Israel’s place,” according to the center.

What is the Hamas charter?

Hamas’ 1988 charter calls for the destruction of Israel, according to the Council on Foreign Relations.

Steven Cook, a senior fellow for Middle East and Africa studies for the council, said in 2021 that Hamas “sees all of Israel and Palestine as Muslim lands, and thus the illegitimacy of Israel and Jewish claims to those lands.”

Who funds Hamas?

Hamas receives material and financial support from Iran, according to the U.S. government and the Council on Foreign Relations. U.S. Deputy National Security Adviser Jon Finer told CBS News on Monday that Iran was “broadly complicit” in the latest conflict, but he also said Iran wasn’t known to be directly involved in the attacks.

“What I can say, without a doubt, is that Iran is broadly complicit in these attacks,” Finer said on “CBS Mornings.” “Iran has been Hamas’ primary backer for decades. They have provided them weapons, they have provided them training, they have provided them financial support. … What we have not seen yet at this moment, although we are continuing to look at it very closely, is any sort of direct involvement in the immediate attacks that took place over the last couple of days.”

Where is Hamas located?

According to the U.S. National Counterterrorism Center, Hamas primarily operates in Gaza but also has a presence in the West Bank, where the Israeli government and Palestinian Authority control different parts of the Palestinian territory.

Other areas where Hamas operates are the Middle Eastern capitals of Doha, Qatar and Cairo, Egypt, as well as Palestinian refugee camps in Lebanon, according to the center.

Is Hamas Palestinian?

Yes. The group formed in 1987 as the Palestinian branch of the Muslim Brotherhood, an Islamist political movement that was founded in Egypt in 1928.

In 2007, Hamas ousted the Palestinian Authority from power in Gaza.

Is Hamas designated a terrorist group?

Yes. Hamas was designated a foreign terrorist organization by the U.S. State Department in October 1997 along with several other groups, including Hezbollah.

In the U.S., the designation makes it illegal for Americans to knowingly provide “material support or resources” to such groups. U.S. financial institutions must also seize control of a designated organization’s funds in their possession and report them to the government.

What is the difference between Hamas and Hezbollah?

Like Hamas, Hezbollah is also an Iran-backed group with a political party and a militant wing that’s been designated a foreign terrorist organization by the U.S., which refers to the group as Hizballah. Hezbollah also opposes Israel, and the two sides have fought against each other before.

But Hezbollah is based in south Lebanon, which borders northern Israel. It operates as a militia alongside Lebanon’s armed forces, according to the CIA World Factbook.

Hamas and Hezbollah follow different divisions of Islam. Hamas is predominately Sunni, the religion’s single biggest group that a majority of several countries follow, including Egypt. Hezbollah is a Shiite group, the religion’s second-largest division that Iran’s population overwhelmingly follows.

Israel-Hamas war’s impact in the U.S.

President Joe Biden has promised additional U.S. financial assistance. Israel is already a leading recipient of U.S. military aide, receiving $3.18 billion in 2022 alone. But not all Democrats are on board.

“As Joe Biden is trying to rally America to support Israel and to transfer weapons, he is finding a growing minority of Democrats oppose, and a growing number of Americans who are protesting,” said Larry Jacobs, professor at the University of Minnesota’s Humphrey School of Public Affairs.

Meanwhile, Republicans are calling out Biden for freeing up $6 billion in aide to Iran last month in return for the release of U.S. hostages.

“There’s the criticism that says that the deal that he just struck with Iran freed them up to provide resources to support Hamas. This is going to unfold for months into the 2024 presidential and congressional elections,” said Professor David Schultz with Hamline University.

Former President Trump is seizing on the attacks to fuel his claim that Democrats are allowing terrorists to enter the U.S. Abou Amara, a Democratic analyst, says Democrats need to emphasize who the bad actors really are.

“There’s some nuance here, right? We have to be able to distinguish between Hamas terrorists, and you know, Palestinians who just want peace and opportunity and security,” said Amara.

Some Republicans are also calling for a more isolationist foreign policy, arguing that the U.S. can’t afford more aide for Israel on top of U.S. aide to Ukraine. It’s a position rejected by Republican analyst Amy Koch.

“This idea of isolationism, I understand that people are afraid and I understand that that’s an easy thing to say. But it isn’t how the world works,” said Koch.