No it's not WWIII, it's not even all out warfare between Israel and Iran. Iran sent a small convoy of weapons, Israel sent an even much smaller one. It was just a token weapons exchange, a pose for international news outlets.
But Iran has sworn extreme escalation if Israel retaliates, and knowing that Israel would retaliate, perhaps this all is just an excuse to provoke something very different. That escalation can take many different forms, and if Iran is just that determined to provoke another front in the war, what comes next may well be yet another proxy war, brutal in an all too familiar way. Is Iran that determined? I'd put the current odds around one-in-three.
On Israel's northern border is yet another terrorist government with its own state established in all but name in Southern Lebanon. Hamas had 20,000 rockets at the start of the war, and they're now estimated to have about 6,000. They cannot do all that much damage except in raids along their borders and suicide bombings. But Hezbollah has 150,000 rockets, it can saturate Israel with constant explosions and bring life in Israel to a near halt as everyone goes has to interrupt their lives with scurrying to bomb shelters. Israel's iron dome, stunningly effective against the Iranian missiles, cannot be nearly as effective against this kind of onslaught, and Israel will have to worry that any one of these missiles carries chemical weapons or is a 'dirty bomb' - not a nuclear weapon, but carrying nuclear radiation all the same.
All of this means, you guessed it, another ground invasion may likely be in Israel's future. Back into Lebanon, with another clearance operation against deliberate human shields, clearing the rockets out of hospitals, schools, and mosques. Even as Israel is worried about casualties within it that could dwarf October 7th, international opinion would grow ever more outraged with what they take to be Israel's murderous bellicosity. If people hate Israel now, they will hate Israel twice as much or more after the next invasion.
Iran's strategy is not full-scale war, Iran's strategy is public opinion, and it's a blinding success. Iran's strategy is to convince the world that Israel is the state with genocidal intentions, not them. Their victory depends on depleting Israel's resources, a process that will take the better part of a century, and if a full-scale war erupts before Israel is a shell of the country it currently is, their strategy is an instant failure. For all Iran's surprisingly advanced weapon technology and intelligence, Israel dwarfs them, and however much destruction they rein on Israel, Israel would rein much more, and Iran's mullocracy would collapse. But Iran knows that mass opinion is fickle, naive, lazy and dangerous, and if Israel's good will to the international public is depleted, so eventually will their resources.
Many people, particularly progressives, refuse to concede that many situations have no good options. They see suffering people and automatically believe that the suffering is inflicted directly. They see this war and believe that Palestinian suffering only has a direct author, rather than shared between Israel and twenty Middle Eastern dictatorships who for three quarters of a century use the Palestinian cause as a convenient means to whip up pan-Arab nationalism, Islamic extremism, and leftist outrage.
A large part of modern history is the history of left-of-liberal progressives finding common cause with totalitarian extremists in the fight against right-wing authoritarianism, thinking that totalitarians can be collaborated with, successfully throwing off the right-wing authoritarians, and then being killed off by the left-wing totalitarians in the maelstrom that inevitably follows - along with everybody else. This is the story of how the Soviet Union came to be with all its satellite states, it's the story of the French Revolution, it's the story of radical Islamic dictatorships, it's the story of anti-colonialist dictatorships all around Africa and the Middle East. The chances of an Islamic dictatorship in America is laughably small, but the naivete is inevitably breathtaking - Western left wingers think they can collaborate in resistance movements with political Islamists, but they can't even coexist with their country's own right wingers without viewing them as enemies. No such left-wing dictatorship seems likely until it happens, and by 2100, it's likely there will be some such Islamic dictatorship for a long period in some Western country, or certainly by 2150. Many European right-wingers exaggerate vastly the threat radical Islam poses to the West, but the threat is real, and will only get realer.
I'm an American liberal, I will always be a liberal, but I am no leftist and haven't been in more than twenty years, because few progressives or socialists seem capable of conceiving that some humans are evil enough to poison the solidarity of well-meaning peoples. They see the suffering of people like Gazans, and cannot fathom that there are evils still well beyond that. All too many of those evils are right wing - and American, but the 20th century was ample evidence that the biggest priority is to eliminate the threat of people being killed by the tens of millions, and in the 21st century, the goal of policies has to be to prevent people being killed by the hundreds of millions.