• Israel's counteroffensive against the Palestinian Hamas militant group will likely stretch for months — if not years, says Ian Bremmer, president and founder of political consultancy Eurasia Group.
• Israel Prime Minister Benjamin Netanyahu declared war on Hamas shortly after the surprise attacks on Saturday, pledging "mighty vengeance."
• The unprecedented nature of Hamas assault on the Jewish Sabbath has raised concerns that Iran may have been involved, given Tehran's long-time support for Hamas and its cause.

Israel's counteroffensive against the Palestinian Hamas militant group will likely stretch for months — if not years, especially if suspicions of Iranian involvement in Hamas' stealth ambush on Israel turn out to be true.

More than 1,100 people have been killed in Israel and the Gaza Strip, with thousands more wounded. Israel is pounding Gaza with air strikes after Hamas fighters launched surprise air, sea and ground incursions on several sites in southern Israel at dawn on Saturday, while also taking dozens of Israeli civilians and soldiers hostage.

"Jews have not faced this kind of atrocity in the world since the Holocaust, so ... everything is on the table if you are an Israeli Jew today," Ian Bremmer, president and founder of political consultancy Eurasia Group told CNBC Squawk Box Asia Monday.

"To take out the leadership of Hamas, it is not going to be a matter of days or weeks. This is months or maybe years. This is going to go on for a long, long time," he added.

Given that these surprise attacks stemmed from a failure of Israeli intelligence and surveillance mechanisms to detect and forestall, Bremmer said there're likely more Hamas operatives already embedded in Israel and they represent "still a very real and present danger."

The weekend assaults also happened a day after the 50th anniversary of the Yom Kippur War, inviting comparisons with the deadliest Arab-Israeli war in 1973 that threatened to imperil the state of Israel.

'Mighty vengeance'

In an address to the Israeli public, Israel Prime Minister Benjamin Netanyahu declared war on Hamas shortly after the surprise attacks on Saturday, pledging "mighty vengeance" and vowing to make "the enemy ... pay an unprecedented price."

Hamas — a Palestinian Islamist militant group that has controlled the Gaza Strip since 2007 — is one of two dominant parties in Gaza. It has been designated a terrorist organization by the United States, the European Union, Israel, Australia, United Kingdom and Japan.

The Gaza Strip and the West Bank collectively form the occupied Palestine territory. The West Bank-based Palestinian National Authority is internationally recognized as the sole legitimate representative of the Palestinian people.

"The Israelis are going to war," Bremmer told CNBC on Monday. "They will be more unified as a government ... so there will probably be a national emergency government with Netanyahu and the opposition fighting that war together."

"And that means not just airstrikes, but also ground occupation — house to house — in Gaza, with lots of casualties that Hamas, of course, wants Israel to be responsible for," he added. "But that does not mean they are going to launch a war against Iran."

Iran suspicions

The unprecedented nature of Hamas assault on the Jewish Sabbath has raised concerns that Iran may have been involved, given Tehran's long-time support for Hamas and its cause.

Ghazi Hamad, a Hamas spokesman, reportedly told the BBC that the group had direct backing for the attack from Iran.

The Wall Street Journal reported Sunday that Iranian security officials helped with the planning and approved the attack at a meeting in Beirut last Monday. Three U.S. officials told NBC News they were unable to corroborate the Journal account.

"Nobody would consider that to be hard evidence at this point," Bremmer told CNBC. While it's a real possibility that Iran is involved, "we are certainly not there right now," he added.

"In terms of other countries' involvement, certainly the level of training for this kind of operation ... quite hard to imagine Hamas would have been able to do this on their own," Bremmer said. "At the very least, you would have expected, Hezebollah to have given them some operational support and training."

Founded in 1982 by Iran's Revolutionary Guards to export its Islamic Revolution, Hezbollah is a Shiite Muslim political party and militant group based in Lebanon that exists to fight Israeli forces that invaded Lebanon.

Hezbollah and the Israeli army exchanged fire Sunday in Shebaa Farms, a small strip of land that sits at the intersection of the Lebanese-Syrian border and the Israeli-occupied Golan Heights. A Hezbollah official reportedly said these were "in solidarity" with the Palestinian people.

"Hezebollah is much more militarily capable than Hamas, so if the Iranians are trying to change the ball game here, you would think Hezebollah would be involved, but they are not. It seems pretty clear — so far — that the Iranians are not looking to get into a broader fight with the Israelis," Bremmer said.

Still, any involvement by Iran would likely trigger a regional war.

"Like everything else in the Middle East, there are 10 sides to every story," Brian Katulis, vice president of policy at the Middle East Institute in Washington, told CNBC on Monday.

"We don't know all the details here, but it would not surprise me if someone in Iran would have been involved in the planning of this. This was not like what we have seen in the past in the Gaza Strip," he added.

"If it's true that Iran is involved, there would be larger implications," Katulis said. "Israel could strike Iran."

Normalization no more

The weekend attacks on Israel by Hamas militants could potentially upend efforts brokered by the United States to normalize ties between Saudi Arabia and Israel.

Hamas spokesperson Hamad told Al Jazeera that these attacks are a message to Arab countries who are looking to normalize relations with Israel.

"I think it is [shameful] for them. I ask all Arab countries to disconnect and cut relationships with Israel, because it is not a state which believes in peace, or coexistence, or believes in being a good neighbor," Hamad said.

U.S Secretary of State Antony Blinken hit the phones with his counterparts in Saudi Arabia, Turkey, United Arab Emirates over the weekend, underscoring grave concerns over the prospect of derailed talks.

"The Israeli-Saudi deal which was close to getting done is now over," Bremmer said separately in a note Sunday. "If anything was accomplished that Hamas wanted, that would be the single biggest thing."

Saudi Arabia has stated it does not support the attacks, and has joined global calls for a de-escalation.

"The kingdom recalls its repeated warnings of the dangers of the explosion of the situation as a result of the continued occupation, the deprivation of the Palestinian people of their legitimate rights, and the repetition of systematic provocations against its sanctities," Saudi Arabia's foreign ministry said in a statement Saturday.