Former Lebanese prime minister Saad Hariri, left, meets with Abu Dhabi Crown Prince Mohammed bin Zayed Al-Nahyan at the Al-Shati palace in Abu Dhabi on Nov. 7. (Mohammed Al-Hammadi/AFP/Getty Images)

Even for a country often used as a battleground by regional powers and their proxies, the sudden resignation of Prime Minister Saad Hariri has opened a new period of political uncertainty and fear in Lebanon. 

The tiny nation has often been caught between the political agendas of more-powerful countries. But it now appears more vulnerable to conflict as Israel and Saudi Arabia try to isolate their shared enemy, the Iran-backed movement Hezbollah.

Hariri, a Sunni politician backed by the Saudis, cited Iranian meddling in Lebanese politics as the reason for his decision to step down.

But the fact that he made his announcement in a televised speech from Saudi Arabia left little doubt that his regional patron must have played a role in a move that caught even his aides off guard.

Saudi Arabia's impetuous Crown Prince Mohammed bin Salman has pursued increasingly bold and aggressive policies at home and overseas, including a purge of officials and business executives in the kingdom, many of them members of the royal family.

When it comes to Lebanon, Mohammed may have calculated that his man in Beirut was doing little more than giving cover to Hezbollah, analysts say. The movement had formed part of a national unity government, with Hariri as its prime minister.

"MBS is an impatient man," said Dan Shapiro, former U.S. ambassador to Israel and a fellow at the Institute for National Security Studies in Israel, referring to the crown prince by his initials. The removal of Hariri "may be a Saudi play to initiate an Israeli response and bloody the nose of Hezbollah."

Israel has watched with alarm as a battle-hardened Hezbollah has helped Syrian President Bashar al-Assad take the upper hand in Syria's war.

Saudi Arabia, meanwhile, sees its rival Iran winning the battle for influence in the region. In Yemen, Iran has backed rebels against a Saudi-led coalition. In Syria, it has supported Assad against Saudi-backed opposition forces, which no longer stand a chance of winning the six-year war.

Israel has been accused of regularly bombing across its northern border, targeting convoys and military depots in Syria linked to Hezbollah. Israeli officials have also ramped up their bellicose rhetoric in recent months, warning that in any war, Israel won't make a distinction between the Lebanese government and Hezbollah. 

Portraits of Iranian-born Lebanese cleric Musa al-Sadr (top left), Iran Supreme Leader Ayatollah Ali Khamenei (top right) and the head of the Lebanese Shiite movement Hezbollah, Hasan Nasrallah, are seen outside a mosque in the southern Lebanese village of Kfar Sir on Nov. 5. (Mahmoud Zayyat/AFP/Getty Images)

Hezbollah and Israel last fought a war in 2006. More than 1,000 soldiers and civilians were killed. 

Hariri's tenure has been an awkward wrinkle in the Israeli narrative that Lebanon is little more than a client state of Iran. His father, former prime minister Rafiq al-Hariri, was assassinated in 2005 in an attack blamed by a U.N. inquiry on Hezbollah operatives.

Hariri's resignation Saturday helps Israel drum up international sentiment against Lebanon, analysts say, particularly as the Trump administration pursues a more aggressive policy on Iran

"Hariri's departure does strengthen the case that Hezbollah is in total domination in Lebanon," Shapiro said. "By removing Hariri, it does make it a bit easier to treat Lebanon as an Iranian outpost." 

Shortly after Hariri announced his resignation, Israel's defense minister, Avigdor Lieberman, took to Twitter. "Lebanon = Hezbollah. Hezbollah = Iran. Iran = Lebanon," he wrote. "Iran endangers the world. Saad Hariri has proved that today. Period."

Israeli Intelligence Minister Israel Katz described Hariri's resignation as a "turning point" in the future of the Middle East. It "exposed the true face of [Hasan] Nasrallah and Hezbollah," he said, referring to the movement's leader, "and Iranian control over Lebanon." 

Now, Saudi Arabia has joined the chorus.

"We will treat the government of Lebanon as a government who has declared war on us because of the Hezbollah militia," Saudi ­Arabia's gulf affairs minister, Thamer al-Sabhan, told the Saudi al-Arabiya channel.

For many in Beirut, whose southern suburbs were flattened during the last war, the thought of further conflict is deeply unsettling.

If the Israelis "don't see a difference between Hezbollah and Lebanon, will they bomb us all?" said Marie Pascal, a shop assistant in the Christian suburb of Ashrafiyeh. "This is making everyone worry because the situation could be much worse this time. I pray it doesn't happen." 

Residents described a waiting game in which one player could push Lebanon's political crisis into open violence. 

"We're feeling calmer than we were on Saturday, but there is always a chance that things will escalate. If Israel takes an opportunity, the situation will be a disaster for us," said Abu Saad, a marble engraver. "The only positive here is that the external interference has for once made the Lebanese feel unified. We all want things to end calmly."

Supporters of Hezbollah were less circumspect.

"Hezbollah went to Syria not to fight but to train for the next war in Lebanon. Israel sees that, and it wouldn't dare attack us now, no matter what it says. But still, everyone is worried. This is a tense time," said Hassan Diab, a taxi driver from Marjayoun in southern Lebanon.

Still, neither Israel nor Hezbollah wants a full-blown war, said Emile Hokayem, senior fellow for Middle East security at the International Institute for Strategic Studies. But that may not be enough to stop one from breaking out, he said.

Hariri's resignation "raises the chances, but I don't think it changes the fundamentals," he said. 

Even Nasrallah pointed to the fact that Israel "has its own agenda." 

"Israel does not work for Saudi Arabia," he said, urging calm in a televised address on Monday, though he added that he did not completely rule out a war. 

Experts and Western diplomats say that Israel is more likely to focus on international efforts to isolate Lebanon and push for sanctions and other measures. 

Shapiro said he expected Washington to reassess its military assistance to Lebanon, whose armed forces are increasingly coordinating with Hezbollah.

But the impact of such moves is limited. "None of this is going to be a strategic game-changer," Hokayem said. "None of this is going to weaken Hezbollah."

Suzan Haidamous in Beirut contributed to this report.