The US has warned Iran in recent days through back-channel talks about the risks of escalation, White House National Security Advisor Jake Sullivan said Sunday on CBS News’s Face the Nation. He said the US couldn’t rule out Iran intervening either directly or via Hezbollah, the Lebanon-based militia group that it sponsors.

Israel’s emergency government has vowed to wipe out Hamas and mobilized 300,000 reservists ahead of a major ground attack. With hostilities centering around the blockaded enclave in Israel’s south, the US has asked Qatar to tell Hezbollah not to open up a second front to the war, a person familiar with the negotiations said, asking not to be named because the talks are delicate.

The danger is that the conflict spreads beyond the region and a sense of panic is palpable in the rounds of shuttle diplomacy. UK Foreign Secretary James Cleverly told Sky News on Sunday he’s urged Israel to minimize civilian deaths to avoid fanning the flames.

“It is in Israel’s interest to avoid civilian casualties and Palestinian casualties, because Hamas clearly wants to turn this into a wider Arab-Israeli war, or indeed a war between the Muslim world and the wider world.” Cleverly said. “None of us, including Israel, want that to be the case.”

Qatar has become a vital conduit for trickier conversations between the US and other nations, and has particular sway in this instance because it hosts the political office of Hamas, which is designated a terrorist group in the US and EU and which perpetrated the shock cross-border attacks that killed 1,300 Israelis last weekend. Regional governments are uniting to try to stop the spreading of the conflict, a person familiar with Gulf efforts said. For Kuwait, there’s a huge fear of Iran getting involved, a different person familiar with these diplomatic negotiations said.

While on a frenetic tour of the Middle East aimed at enlisting the help of Arab nations in containing the fallout, US Secretary of State Antony Blinken also held his first call on the issue with his Chinese counterpart, asking Foreign Minister Wang Yi to deploy Beijing’s influence in the region toward the same goal.

The Israeli army is poised to stage a large-scale offensive in Gaza after suffering its most deadly attack in decades when Hamas struck into southern Israel on Oct. 7. Already more than 2,300 Palestinians have died in Israel’s retaliatory bombing of Gaza, amid concerns that the attack will spark a humanitarian catastrophe.

Iran, which provides money and weapons to Hamas and Hezbollah, has vowed that its so-called “axis of resistance” will respond to Israel’s “war crimes.”

If Israel pursues its invasion of Gaza “no one can guarantee control over the situation and prevent the conflict from spreading,” Iran’s Foreign Minister Hossein Amirabdollahian said in a meeting with Qatar’s Emir Sheikh Tamim bin Hamad Al Thani in Doha.

Israeli officials say they hope the US deployment of warships to the eastern Mediterranean will deter Iran and its proxies, but they’ve rushed reinforcements to their northern border with Lebanon and Syria all the same. The Iranian foreign minister also met Hezbollah leader Hassan Nasrallah in Beirut on Friday to discuss a response to Israel’s actions, the state-run Iranian IRNA news service said.

Turkey believes the US deployment of warship strike groups in the eastern Mediterranean is encouraging Israel to use excessive force in its response to attacks by Hamas. While the US says it is a deterrent force, Turkey fears that the presence of US warships are only working to fuel tensions rather than lowering them.

Mortars were fired on Saturday and Sunday over Israel’s northern border with Lebanon and a squad of infiltrators was stopped by Israeli aircraft, according to the IDF. Hezbollah has an arsenal of more than 100,000 rockets and missiles, some of which can reach central Israel, where Tel Aviv is located. Israel and the Lebanon-based group fought a month-long war in 2006.

Israel has framed the unprecedented assault as its Sept. 11. It says its goal is to destroy Hamas’s military and political leadership in the coastal Gaza Strip where it’s held control since 2007. That war aim could take months, and risks unleashing major casualties.

The aim of containing spillover is central to the many conversations France’s President Emmanuel Macron has been having with regional leaders since the atrocities began, according to a top French official who asked not to be named.

France has also communicated this message to Hezbollah and Iran, the official said, while European Union leaders are scheduled to hold a video meeting to discuss the crisis on Tuesday.

In a call with Israeli Prime Minister Benjamin Netanyahu Saturday, President Joe Biden pledged “unwavering” US support for Israel. In a separate call, he also offered Palestinian Authority President Mahmoud Abbas “full support” for bringing humanitarian aid to Gaza, which has been under a years-long blockade and to which Israel has cut off water, fuel and electricity in recent days.

Speaking at a dinner in Washington, Biden accused the Palestinian militants of using “innocent Palestinian families,” of whom “the vast majority that have nothing to do with Hamas” as human shields. His envoy Blinken plans to make a second stop in Israel on Monday for further consultations with senior Israeli officials.

Averting War on Two Fronts

Retired Major General Yaakov Amidror, who was Netanyahu’s national security adviser a decade ago, said Israel is preparing whatever is needed logistically and operationally to deal with any threat from Lebanon. “They are forces movable in minutes if it will be needed. Of course it is not easy to deal with two fronts at the same time” but Israel’s army “can do it,” he said.

Some commentators are taking a more aggressive approach. Ariel Kahana, senior diplomatic correspondent for right-leaning Israel Hayom newspaper, said Israel must not wait for Hezbollah to attack.

Iran’s Islamic Revolutionary Guard Corps and Hezbollah have deployed forces to the southwestern Syrian border, the Washington-based Institute for the Study of War reported Oct. 9. The deployments are consistent with the scenario in which the Gaza conflict expands into a multi-front war surrounding Israel, it said.

National Security Adviser Tzachi Hanegbi said in a late night briefing Saturday that Israel’s goal is avoid getting “drawn into a double-theater war” and its focus is the south.

“We hope that Hezbollah doesn’t bring about Lebanon’s destruction because it won’t be less than that if they attack from there,” he warned.

— With assistance by Iain Marlow, Ethan Bronner, Selcan Hacaoglu, and Michael Nienaber