Benjamin Netanyahu, Israel's prime minister, is scheduled to address a joint sitting of the US Congress on July 24. He will be the first foreign leader to speak to Congress four times.
It will be an awkward time for politicians in both the US and Israel. President Biden is fighting for his political future both in his own party and against Donald Trump. Prime Minister Netanyahu could soon be forced out of office if his coalition collapses.
So Netanyahu is desperate to convince Congress to keep supplying his country with armaments and political support.
A great deal hangs on his speech. The US is not solidly behind Israel. Dozens of Congressional Democrats have declared that they will boycott Netanyahu's speech. About 40,000 Gazans have died in Israel's assault, both civilians and Hamas militants. On October 7 around 1,200 Israelis were massacred. How can Israel morally justify a ratio of 35 Palestinian deaths for every Israeli one?
There is an answer to this. It can be justified if Israel is fighting a just war.
In a recent column in the Wall Street Journal, Lance Morrow, a distinguished journalist who used to write for Time magazine, argued that high civilian casualties are simply the price the world has to pay for exterminating vile evil-doers. "A just war, no less than an unjust one, may involve tragic arithmetic," he wrote.
And according to Netanyahu, Israel is "waging a just war against Hamas, a genocidal terrorist organisation that perpetrated the worst attack on the Jewish people since the Holocaust."
But the war in Gaza is not just simply because Netanyahu says so. There is a vast amount of literature on what constitutes a just war. Most writers agree that just wars involve these criteria:
Governments have argued that if they can tick all these boxes, or at least most of them, their wars will be just. Just war theory underpinned George W. Bush's decision to go to war in Iraq.
However, the death toll in Gaza has been so horrific that some supporters of "just wars" are having second thoughts.
That theory was first proposed by the Catholic theologian Augustine of Hippo in the 5th century. Other writers have built on his insights up to the present day. Since just wars originated with Catholics, it might be useful for Netanyahu to know what Catholics think about it today.
The short answer is that they are deeply sceptical.
A Catholic agency called the Justice and Peace Commission of the Holy Land has just published a paper questioning whether the notion of a "just war" is still relevant in an era of asymmetric warfare and weapons of mass destruction. "We must express vigilance with regard to those who manipulate the concept of just war to suit their needs," says the document.
The number of Catholics in Israel is tiny - less than 150,000. But Catholics have a deep and abiding connection to the Holy Land and have always lived there. Netanyahu and his cabinet should listen to them. The Commission claims that the idea of a "just war" is being weaponised:
we are outraged that political actors in Israel and abroad are mobilizing the theory of "just war" in order to perpetuate and legitimate the ongoing war in Gaza. This theory is being used in a way in which it was never intended: to justify the death of tens of thousands, our friends and our neighbours.
The document questions the proportionality of Israel's response to the atrocities of October 7. Describing it as "proportional" is Orwellian:
There are those pretending that the war follows the rules of "proportionality" by arguing that a war that continues until the bitter end might save the lives of Israelis in the future, therefore balancing the scales of the thousands of Palestinian lives being lost in the present. In doing so, they privilege the security of hypothetical people in the future over the lives of living and breathing human beings who are being killed every day. In short, the manipulation of the language of just war theory is not only about words: it is having tangible, fatal results.
And the invocation of just war theory sidesteps the quest for peace:
Another criticism of just war theory is that it can divert the conversation to whether or not a war is being fought ethically and thus avoid confronting the question of whether it should be fought at all.
In the light of the way that wars are being fought in the 21st century, can there ever be such a thing as a just war? Maybe not, says the Commission. "The dubious application of 'just war' theory to modern conflicts, especially to those that have dragged on for decades, has provoked thinking that suggests that 'just' wars might only exist in very rare cases."
Even though Saint Augustine's criteria have been enshrined in the authoritative documents of the Catholic Church, like its official Catechism, the Vatican might be considering modifying or updating them.
In fact, Cardinal Pietro Parolin, the Vatican's foreign minister told the media a few days ago: "There is [such a thing as a] just war, the war of defence, but today with the weapons that are available, this concept becomes very difficult. In fact, it's being discussed. I don't think there is a definitive position yet, but it's a concept that's in revision."
Saint Augustine's just war theory is still valid - but he was thinking of wars between Romans and Vandals - hordes of sword-slashing soldiers attacking each other on the battlefield. He knew nothing of 2,000-pound bombs. It's time for an update of his theory.