Joe Biden stood in the White House Rose Garden last week to announce a ceasefire deal, but it wasn’t the one he has been desperate to secure for months. Biden confirmed that Israel and Hezbollah had accepted a US-brokered agreement to stop a war that has devastated large parts of Lebanon. But the deal does nothing to end Israel’s calamitous war on Gaza, where Biden and his administration had purportedly been pushing for a ceasefire – while enabling Israel with US weapons and political cover for 14 months.

Biden could have achieved a ceasefire in Gaza months ago if he had truly applied pressure on the Israeli prime minister, Benjamin Netanyahu. On 26 November, Netanyahu made clear the importance of an uninterrupted flow of US weapons to Israel, saying the 60-day truce with Hezbollah would give Israeli troops “a breather” and provide time to replenish arms supplies from Washington.

As the ceasefire in Lebanon took effect on 27 November, US officials leaked that they were moving ahead with a new $680m weapons package to Israel, which includes thousands of joint direct attack munition (Jdam) kits and hundreds of small-diameter bombs. Jdams are guidance kits built by Boeing that attach to large “dumb bombs”, which can range up to 2,000lb (907kg), and convert them into GPS-guided weapons. These bombs cause enormous casualties when dropped on population centers, as Israel has repeatedly done in Gaza and Lebanon.

This latest weapons deal will be the Biden administration’s farewell gift to Netanyahu – allowing Israel to continue its assault on Gaza, while Biden gripes about his failure to secure a ceasefire.

Since Biden declared his unwavering support for Israel after the Hamas attack of 7 October last year, the US president consistently refused to use the leverage he had over Netanyahu – stopping the flow of US weapons, jet fuel and other military support that allowed Israel to sustain its wars in Gaza and Lebanon. Instead, Biden repeatedly rewarded Netanyahu’s obstinacy by sending him more weapons. In August, as Netanyahu sabotaged ceasefire negotiations with Hamas by adding new conditions, the Biden administration approved one of the largest arms deals with Israel in US history: a $20bn package that will include dozens of F-15 fighter jets, tactical vehicles, missiles, and tens of thousands of mortars and tank cartridges.

A group of progressive US senators, led by Bernie Sanders, unsuccessfully tried to block portions of that $20bn package last month in the Senate. Congress has never managed to stop a US weapons transfer to Israel, which is the largest cumulative recipient of American foreign aid in the world. Israel has received about $310bn (adjusted for inflation) since it was founded in 1948.

The latest $680m weapons deal revealed last week will be funded by US taxpayers, who have borne enormous costs for US military support for Israel since October 2023. Washington provided Israel with nearly $18bn in weapons and other assistance since the Hamas attack, according to a recent study by the Costs of War project. And the US spent another $4.8bn on its own military operations in the Middle East due to the conflict.

It is one of Biden’s greatest foreign policy and moral failures that he refused to leverage $22.7bn in military support (and many more billions in future arms deals) into pressuring Netanyahu to accept a ceasefire in Gaza. Instead, Biden abandoned the most powerful diplomatic tools he had – and allowed Netanyahu to expand the Gaza war into Lebanon.

From the start of Israel’s invasion of Gaza, Biden and his aides argued that their top priority was to prevent the war from spiraling into a regional conflict. But within months, the battle spilled into clashes in Lebanon, Iraq, Syria, Yemen and the Red Sea – as militias allied with Iran tried to pressure Israel and the US into ending the attack on Gaza.

On 8 October last year, Hezbollah began firing rockets into northern Israel, in what the group’s leaders said was an effort to divert Israeli military resources from Gaza. Israel retaliated with heavy airstrikes and artillery shelling across southern Lebanon and the Bekaa valley, largely Shia Muslim areas where Hezbollah has significant support. Hezbollah, a Shia militia founded in the 1980s with the help of Iran’s Revolutionary Guards to fight the Israeli occupation of southern Lebanon, has since grown into the most powerful political and military force in Lebanon.

For months, the daily exchange of fire across the Israel-Lebanon border fluctuated, as Hezbollah tried to avoid instigating a wider conflict with a far more powerful Israeli military. But the group’s longtime leader, Hassan Nasrallah, insisted it would end its attacks only when Israel stopped its war on Gaza.

By refusing to separate negotiations for a truce along the Israel-Lebanon border from a ceasefire in Gaza, Nasrallah had miscalculated Netanyahu’s willingness to expand the war – and Biden’s inability to restrain an ally dependent on US weapons and political cover. In the lead-up to the US presidential election, Netanyahu seized on Biden’s unconditional support to launch an all-out war against Lebanon in an attempt to destroy Hezbollah and return 60,000 displaced Israelis to their homes in the north.

The opening salvo began on 17 September, when Israel detonated thousands of pagers and handheld radios of Hezbollah members over two days, killing dozens and wounding more than 3,000 people. While western analysts and media outlets compared the explosions to a James Bond thriller – expressing admiration for Israel’s technological prowess and cunning – the indiscriminate bombings were likely war crimes. Lebanese hospitals were overwhelmed with thousands of victims, many of whom had suffered severe injuries to their eyes, faces and limbs.

Israel took advantage of the fear and chaos sown by its pager attacks, and dramatically escalated its assault on Hezbollah and Lebanon. On 23 September, the Israeli military carried out one of the most intense aerial bombardments in modern history, bombing nearly 1,600 targets across Lebanon. The attacks killed more than 550 people and injured 1,800 – the highest single day death toll since the end of Lebanon’s 15-year civil war in 1990. By the next day, nearly 500,000 Lebanese civilians had fled their homes.

It became clear that Israel was planning to use the same playbook in Lebanon that it had deployed for nearly a year in Gaza: massive aerial bombardment and displacement of civilians, followed by a ground invasion. On 25 September, the US and France, along with several Arab states, announced a plan for a 21-day ceasefire, which would have allowed time to negotiate a wider agreement between Israel and Hezbollah. While the Biden administration thought that Netanyahu supported a truce, the Israeli government was making plans to kill Nasrallah.

Two days later, on 27 September, Israeli warplanes carried out an enormous airstrike on a building complex in Beirut’s southern suburbs, using more than 80 bombs – including US-made 2,000lb “bunker buster” munitions – to kill Nasrallah and other Hezbollah leaders. Lebanon’s foreign minister later revealed that Nasrallah had agreed to the US-proposed ceasefire shortly before Israel assassinated him.

After killing Nasrallah, Israel intensified its air strikes throughout Lebanon and launched a ground invasion of the south. Over the past two months, Israel assassinated most of Hezbollah’s top leadership and destroyed a significant portion of the militia’s arsenal of more than 100,000 missiles and rockets. The Israeli military has concentrated its attacks on Shia-dominated parts of Lebanon, causing severe economic damage and trying to impoverish the communities from which Hezbollah draws it recruits and base of support.

The war has killed nearly 3,800 Lebanese and displaced more than 1 million people, nearly a quarter of the country’s population. The World Bank recently estimated that the conflict has caused $8.5bn in economic losses to Lebanon, including nearly 100,000 housing units that have been damaged or fully destroyed by Israeli bombardment. Beyond the economic toll, entire blocks of the Beirut suburbs and the ancient city of Tyre have been flattened by Israeli air strikes. Israel also demolished large sections of the southern city of Nabatieh, which dates to the Ottoman era.

Israel’s destruction continued up until the final hours before last Wednesday’s truce took effect. The previous day, the Israeli military carried out some of the heaviest airstrikes of the entire war, bombing buildings across Beirut, in neighborhoods full of displaced people, and sending thousands of Lebanese fleeing in a panic.

The 60-day ceasefire, which is supposed to lead to a longer-term agreement between Israel and Lebanon, calls for Israeli troops to withdraw from southern Lebanon and Hezbollah’s fighters to move north of the Litani River. That would allow the Lebanese army to move into the border areas, and ensure calm along with a UN peacekeeping force that has been operating in southern Lebanon for decades. The agreement calls for an international committee with military officials from the US, UK, France and other countries to monitor the ceasefire.

Hezbollah, battered by war with a militarily superior enemy and the killing of its top leaders, finally bowed to Netanyahu’s demand that it decouple an agreement along the Israel-Lebanon border from a truce in Gaza. But an emboldened Netanyahu could resume the war virtually any time: He insists that Israel has “full freedom of military action” – blessed by the Biden administration – if it believes Hezbollah is breaking the agreement.

Already, France has accused Israel of violating the truce more than 50 times since it took effect last week, firing at Lebanese returning to their home villages or attacking sites that the Israeli military claimed were connected to Hezbollah. The Lebanon ceasefire is tenuous, especially since the US has shown little willingness to restrain Netanyahu anywhere in the Middle East.

Biden will soon find that the region won’t have even short-term peace until there’s a ceasefire in Gaza. That truce was within Biden’s reach, if only he had stood up to Netanyahu.

• Mohamad Bazzi is director of the Hagop Kevorkian Center for Near Eastern Studies, and a journalism professor at New York University. He is also a non-resident fellow at Democracy for the Arab World Now (Dawn)