For decades, Hezbollah’s grip on Lebanon was iron-tight.

With its vast arsenal, the militant group was more powerful than the country’s national army. He controlled or kept under control Lebanon’s most important government agencies, as well as critical infrastructure, such as the border with Syria and the commercial port. Almost no major political decision could be made without her support, and no political party could seriously challenge any move she or her patron Iran made.

But that longstanding status quo has now been shaken – a reversal for Hezbollah that has opened a new political chapter in Lebanon.

Fourteen months of fighting against Israel destroyed the once untouchable Shiite Muslim group. Rebels overthrew his main ally in neighboring Syria, dictator Bashar al-Assad. Iran also now finds itself weakened as it and its allies have been hit hard by Israel.

Hezbollah is on the most volatile ground in years as power dynamics realign in the Middle East after more than a year of war and turmoil. And while the group remains powerful — it still has many thousands of fighters and commands the loyalty of most of the country’s Shiite Muslims — analysts say one thing is clear: The era of Hezbollah and Iran’s unwavering dominance in Lebanon appears to be over.

“It’s a new political reality,” said Mohanad Hage Ali, a senior fellow at the Carnegie Middle East Center in Beirut. “It will take time for this new reality to unfold,” he added, “but what we have seen so far is enough to show us that the tide has turned.”

That political quicksand was laid bare on Thursday, when Lebanon’s parliament elected a new president, overcoming years of political deadlock that many critics attributed to Hezbollah’s efforts to block any attempt at a resolution. Political paralysis has left the country under the leadership of a weak and ineffective interim government for more than two years.

In Lebanon, many saw the election on Thursday General Joseph Aouncommander of the Lebanese army, as a key step towards the country’s stability. It was also seen as a concession by Hezbollah and, some analysts said, an acknowledgment that the group was no longer in a position to paralyze the state.

Since the founding of Lebanon, a multitude of factions and sects from more than a dozen religious groups in the country have fought for power and influence. Its fragile political system relies on agreements between parties and sects, as well as their foreign backers. That system has held the country together as it lurched from crisis to crisis since a 15-year civil war ended in 1990.

Over the past three decades, Hezbollah — which is both a political party and a militant group — has outplayed its domestic enemies and forged strategic alliances to cement its position as the real force supporting the country’s weak and disunited state.

Even as the government struggled to keep the lights and water on, Hezbollah built a vast network of social services — including high-quality health care and free education — for its mostly Shiite supporters.

But over the past three months, the group has suffered a series of devastating blows.

His war with Israel wiped out Hezbollah’s top brass, destroyed large parts of its arsenal and left the country with a multibillion-dollar reconstruction bill. His crushing defeat also shattered Hezbollah’s promise to the Lebanese that it alone could defend Lebanon against Israel—a claim that served as the group’s official raison d’être.

Then last month, the group lost its main land bridge for arms and money, as well as a political ally, when Syrian rebels, whom Hezbollah once fought, toppled the Assad government.

Hezbollah’s patron Iran is also on the defensive against the overthrow of Mr. al-Assad and considering his own escalation of tensions with Israel, including direct conflict through rocket fire.

Iran’s network of anti-Israeli militias, known as the Axis of Resistance – Hezbollah was a key player – unraveled, bringing with it Tehran’s ability to project power as far west as the Mediterranean Sea and south to the Arabian Sea.

Without those pillars of support, Hezbollah’s ability to influence Lebanese politics is diminished, even as the group and its allies try to cast themselves as agenda-setters in the country. Their waning influence was visible even before the vote when the Hezbollah-backed presidential candidate withdrew from the race late Wednesday night.

Hezbollah’s “narrative has been seriously discredited, its military has been seriously weakened and, in my view, it will have to start paying the price politically,” said Sami Nader, director of the Political Science Institute at Saint Joseph University in Beirut.

Most experts agree that even in its weakened state, Hezbollah remains the most dominant political force in Lebanon. But this, they say, is less proof of the group’s hold on power and more a reflection of political dysfunctionality and internal conflicts in the country. That dysfunction was on full display during Thursday’s parliamentary vote, which often boiled down to bickering before the vote.

General Aoun’s election as president on Thursday is the first step in charting a new political map for the country and the region, analysts say. General Aoun is widely believed to have the support of the United States and Saudi Arabia. The Saudis once vied for influence in Lebanon before being overshadowed by Iran and Hezbollah.

In his victory speech, General Aoun hinted at the vision he and his allies share for a new political era in Lebanon and said the day marked “a new phase in Lebanon’s history.”

He called the Arab countries, which Iran once pushed out of Lebanon, “brotherly” nations. He spoke of the “right of the state to monopolize the possession of weapons” – a subtle reference to calls for Hezbollah to disarm after its 60-day ceasefire with Israel ends later this month. And he envisioned a country that could be defended by its own national army, without militias like Hezbollah that have long dragged the country into internal strife and war.

“My promise is to call for a defense strategy and the establishment of a state – I repeat, a state – that invests in its military, controls all borders and implements international resolutions,” General Aoun said.

Still, experts warn that the country is still in the early days of this new political chapter – and that Hezbollah may yet recover. The coming months will be filled with critical litmus tests for the group, including whether it can help rebuild large swaths of the war-torn country and withdraw completely from southern Lebanon, as stipulated in the cease-fire agreement.

“Hezbollah has been dealt stunning blows in terms of its strategic powers and ability to stand up to Israel,” said Paul Salem, vice president for international engagement at the Near East Institute in Washington. “But inside Lebanon, it’s still a very heavily armed group, more powerful than any other in the country.”