There have been many moments of extreme danger over the past year. This is the worst.

In the past seven days, Hezbollah leader Hassan Nasrallah has been assassinated, Israel has launched a ground invasion of Lebanon, and Iran has fired nearly 200 ballistic missiles at targets across Israel.

Western and regional powers – led by the US – have pushed for de-escalation. The UN Security Council called for an “immediate end” to hostilities and the G7, which includes the US, UK and Germany, has called for “restraint”.

But so far those efforts have failed – and the Middle East stands closer than ever to all-out war.

Here’s how the last week played out.

As the sun set over Beirut on 27 September, the south of the city was hit by a series of huge explosions.

Several apartment buildings had been struck, leaving a huge crater in the ground. Plumes of dust and debris filled the skyline, visible from across the Lebanese capital.

The strike, aimed at an underground bunker, killed Hezbollah leader Hassan Nasrallah.

Seen as a prize-target, Nasrallah had not been seen in public for years for fear of being assassinated by Israel.

His death capped a week of ramped-up Israeli strikes targeting Hezbollah that had left more than 500 people dead.

The week before that, a series of walkie-talkie and pager explosions targeting the group left at least 32 dead and over 3000 injured.

Nasrallah’s death wiped all hopes of a de-escalation, which just hours earlier had seemed possible.

A US proposal for a 21-day ceasefire had been discussed on the sidelines of the United Nations (UN) General Assembly in New York. Israel’s UN ambassador Danny Danon had even said his side was “open to ideas”.

But hours after the strike, Israeli Prime Minister Benjamin Netanyahu was on an early flight home from the UN – and any lingering hopes of diplomacy prevailing faded away.

Three days later, Israeli forces crossed into Lebanon, marking the start of a ground invasion.

The Israel Defense Forces (IDF) said its operations would be “limited and targeted”.

Fighting so far has driven nearly 1.2 million people from their homes, according to Lebanon’s crisis unit. At least 8 Israeli soldiers have been killed.

Israel says the operation is aimed at stopping Hezbollah’s ability to launch rockets and drones over the border – something it has done on an almost daily basis since Hamas, its Palestinian ally, launched a deadly raid into southern Israel almost a year ago, triggering the current Gaza war.

Now Israeli troops are fighting a ground war on two fronts simultaneously: Gaza and Lebanon. That hasn’t happened in decades.

The last war between Israel and Hezbollah, in 2006, ended inconclusively with UN Resolution 1701, which stipulated Hezbollah withdrew its forces from southern Lebanon.

That never happened, and with Iranian support, Hezbollah grew in strength.

Israel has not said that it wants to remove Hezbollah entirely from Lebanon’s political landscape (as it has with Hamas in Gaza), but for all its talk of this being a “limited and targeted” operation, it’s clear that Israel is ruthlessly determined to cut Hezbollah down in size.

Spurred by an astonishing two and a half weeks, Israel is in an ambitious frame of mind.

The next day, at around 19:30 local time, 10 million Israelis were sent running for bomb shelters across the country after Iran launched nearly 200 ballistic missiles at Israel.

The nation’s air defence system sprang into action – and allies including the US and UK were involved in repelling the attack – another sign of the broadening scope of the conflict.

The IDF said most of the missiles were intercepted, but that a small number struck central and southern Israel. The only person reported to have been killed was a Palestinian man in the occupied West Bank.

With its biggest proxy group in disarray, Tehran calculated that to restore some semblance of deterrence it needed to do something more dramatic than its last well-telegraphed missile and drone attack on Israel in April.

Hence the larger number of ballistic missiles and the lack of advance notice.

But while the attack was more than purely demonstrative, it did not appear to signal Iran’s desire for an all-out fight.

That’s hardly surprising. If it came to a full-on war, Iran knows that it would lose, and badly.

It could even herald the end of the Islamic Republic.

Israel, with powerful western allies – and a smattering of Middle Eastern neighbours willing to help shoot down Iranian missiles – is a regional superpower.

Iran, economically fragile and led by an unpopular government, is no match. Nor does it have the sort of allies that would be willing to spring to its defence in the event of a confrontation.

The supreme leader, Ayatollah Khamenei, made suitably defiant noises at Friday prayers in Tehran, but Iran knows it cannot afford to escalate much further.

Despite Hezbollah’s devastating losses, it has vowed to fight on in Lebanon.

And history shows us it is easy for Israel to enter Lebanon, but difficult for them to leave.

As for Israel’s response to Iran, the region – and the world – has been on tenterhooks since Tuesday.

US president Joe Biden said he has discouraged Israel from striking Iranian nuclear or oil facilities as part of its retaliation.

A severe reaction seems inevitable, though, and some of Benjamin Netanyahu’s recent rhetoric suggests that he might be thinking, ultimately, of regime change in Iran.

But Israel’s immediate objectives are closer to home. “Total victory” in Gaza and removing the threat posed by Hezbollah along the northern border.

Israeli leaders point out that they at war on many fronts. Benjamin Netanyahu says there are seven: Gaza, Lebanon, the West Bank, Yemen, Iran, Iraq and Syria.

It’s true that over the past year, attacks have come from all these directions, even though pro-Iranian groups in Iraq and Syria have so far posed little real threat.

We’re not seeing an all-out regional war just yet, but with so many players feeling they have a stake in it, the war in Gaza has metastasised in a dramatic fashion.