Perhaps you remember the time, long, long ago, when we used to talk of something called the Middle East peace process.
It was a time when Israeli and Palestinian officials would sit down and negotiate, not very successfully, admittedly, but in the hope that they might be able to find a way to resolve their many deep-seated differences about how to share the bit of the Levant that they both call their homeland.
Last night, in the Gaza Strip and southern Israel, many thousands of people, Palestinians and Israelis, lay awake in their beds, listening for -- and dreading -- the sound of an incoming missile or rocket. There is no peace process any more, nor has there been for several years; in its place there is either a vacuum, or war.
Next year will mark the 20th anniversary of the signing of the Oslo peace accords, a moment when, just briefly, many Israelis and Palestinians believed there might be a chance of coming up with a way to live in peace, side by side.
The Palestinian leader Yasser Arafat was awarded the Nobel Peace Prize (together with Israelis Shimon Peres and Yitzhak Rabin) and took up residence in the West Bank city of Ramallah. He died eight years ago, and now they're digging up his body to see if he was poisoned by the Israelis.
Why did the Palestinian group Hamas, which has controlled the Gaza Strip for the past five years, unleash a barrage of more than 100 rockets against Israel last weekend? Why did Israel choose to respond with its most violent military onslaught since its war in Gaza four years ago?
According to the analyst Hussein Ibish, of the American Task Force for Palestine, whom I interviewed on the programme last night, Hamas hardliners needed to prove that they still have the stomach for a fight, even after five years of trying to be a quasi government, looking after sewers, and power supplies, and health and education. And perhaps they also wanted to force their Muslim Brotherhood patrons in Cairo to come off the fence and back them as the legitimate representatives of their people.
As for the Israeli prime minister Benjamin Netanyahu, according to Daniel Levy of the European Council on Foreign Relations, who was also on last night's programme, with an election coming in January, Mr Netanyahu may well have caculated that a short, sharp military adventure would do him no harm at all at the polls. It will certainly divert voters' attention from Israel's deep religious-secular divide, which has been a dominant political theme for the past year.
If this all sounds cynical, well, I'm sorry, but there's more to come. The Israeli newspaper Ha'aretz says the Hamas military commander whom the Israelis killed on Wednesday, Ahmed al-Jaabari, had been for several years Israel's go-to man in Gaza. Apparently, he was the man who kept the rockets on their launchers, who kept the captured Israeli soldier Gilad Shalit alive, and who eventually, just over a year ago, negotiated Shalit's return to Israel in exchange for more than 1,000 Palestinian prisoners.
According to Ha'aretz, Israel eventually decided that Jaabari was no longer fulfilling his side of the bargain: too many rockets were once again being fired from Gaza into Israel. The message, said Ha'aretz, was simple and clear: "You failed -- you're dead."
So now what? Well, we know the script, unfortunately, because we've watched this drama many times before. Over the next few days -- maybe a week, maybe two -- more people on both sides will die. More people will live in fear, and more will have reason to hate their adversaries.
Eventually, a ceasefire will be agreed. Israel will say it has largely destroyed the Hamas arsenal of rockets and has seriously weakened its military capacity. Hamas will say it has withstood yet another onslaught by its far more powerful enemy, and will salute the resolve and steadfastness of the Palestinian people.
I remember asking a senior Israeli peace negotiator many years ago if he thought the conflict between Israelis and Palestinians would ever end. "Oh yes," he said. "It will end when we grow tired of killing each other's children."
That time, it seems, has not yet come.