Shortly after gunmen from the Popular Front for the Liberation of Palestine shot down Israel's Tourism Minister, Mr Rehavam Ze'evi, in his Jerusalem hotel on October 17th, Israel launched a large-scale military operation in the West Bank.
Troops entered Palestinian-held territory in no fewer than six major cities, their incursions frequently accompanied by running battles with Palestinian gunmen, with numerous civilians killed in the crossfire.
The response from the American government was fast and furious. Israel, declared the State Department's spokesman, the White House spokesman, the Secretary of State and finally the President himself, had to withdraw from the Palestinian areas right away, and never go back.
Shortly after three Palestinian suicide bombers blew themselves up in Jerusalem and Haifa last weekend, killing 25 civilians and injuring at least 200 more, Israel formally branded Yasser Arafat's Palestinian Authority "an entity that supports terrorism" and destroyed Mr Arafat's helicopters in their hangars at his Gaza City presidential compound, bombed the runway at Gaza's international airport, and raided numerous other targets across the West Bank and Gaza Strip.
The response from the American government has been to remind Israel gently that it will need eventually to "get back to a process" of negotiation, but otherwise to murmur sympathetically about the country's right to self-defence and its obligation to protect its civilians from terrorist attack.
As the grounded Mr Arafat wondered plaintively yesterday: "Where is the international reaction?"
Presumably, he was thinking most of all about this extraordinary shift in the Bush administration's attitude to the Israeli-Palestinian conflict - from outright hostility to Mr Sharon's policies a few weeks ago to tacit support for a strategy that now seems clearly designed to bring an end to Mr Arafat's rule.
Israel has sustained horrifying suicide bombings before - a June blast outside a Tel Aviv disco and an August attack on Jerusalem pizza restaurant come readily to mind - without managing to secure the apparent carte blanche for action against Mr Arafat that it now has.
So what has changed the Americans' minds this time?
One possibility is that Mr Sharon proved remarkably persuasive during a meeting he had with President Bush at the White House on Sunday, when depicting Mr Arafat as an unreformed arch-terrorist.
But since the Prime Minister has been repeating that same derisive assessment of the Palestinian leader for years, this seems highly unlikely.
Far more probable is that the Bush administration's new and inexperienced man on the ground here, the retired Marine Corps Gen Anthony Zinni, has played a decisive role.
Described by his immediate boss, the Secretary of State, Colin Powell, as "a bulldozer" who would tolerate no nonsense, Mr Zinni has been holding a series of meetings with both Israeli and Palestinian political leaders and security chiefs.
He appears to have become convinced that, overall, it is the Israelis who are sinned against and the Palestinians who are sinning - that Mr Arafat has been doing next to nothing to thwart Islamic extremists' attacks on Israel, indeed has been inciting such attacks through his state-controlled media, and that Mr Sharon's oft-aired analogy between the Palestinian Authority and the Taliban has some merit.
If so, Mr Zinni has now placed the US administration firmly back in its historic role as Israel's primary strategic ally and defender, at odds with the position held by the United Nations, members of the European Union and others, where Mr Sharon and Mr Arafat are broadly regarded as two sides of the some uncompromising coin, equally responsible for the ever-deepening hostilities.
So deeply convinced are the Americans now said to be of Mr Arafat's culpability that Mr Zinni is even reported to have been sending out feelers to other Palestinian leaders, including Abu Mazen and Abu Ala, the Palestinian Authority president's most senior colleagues, and West Bank security chief Jibril Rajoub, about their desired roles in a post-Arafat era.
For the record, neither these men, nor any other prominent Palestinian leaders, have been willing to so much as muse aloud about life after Arafat.
And while, behind the scenes, there are some senior Palestinian voices lamenting that the rais has driven his people into a dead end, the decades-old problem surrounding Mr Arafat remains: he, and only he, has the personal history, authority and support to conclude agreements that will be accepted by his people.
Evidently aware that an active Arafat in exile would not be a significantly different adversary from an active Arafat in the West Bank and Gaza, Mr Sharon has elected thus far not to force out his nemesis, but rather to limit his movements: hence the strikes on the helicopters and the airport runways.
But however often the Prime Minister's aides may assert to the contrary, the military campaign now under way is clearly designed to accelerate the collapse of Mr Arafat's regime in the apparent, but far from certain, expectation that, somehow, somewhere, a more accommodating Palestinian leadership may subsequently emerge.
As the marginalised Israeli politicians on the left are now gloomily recalling, Mr Sharon attempted a not dissimilar ploy in Lebanon in 1982, with spectacularly costly consequences.
The Likud-Labour partnership at the heart of Mr Sharon's government has been deeply cracked by the new assault on Mr Arafat.
But even if the Foreign Minister, Mr Shimon Peres, ultimately elects to lead his party into opposition, there is little prospect of Mr Arafat being saved by a domestic Israeli political crisis.
Labour retains the status of the Knesset's largest party only by a quirk of Israeli electoral law: the elections that brought Mr Sharon to power last spring were prime ministerial elections only; parliament was not dissolved.
If this coalition did collapse, and general elections were held, either Mr Sharon or the equally uncompromising Mr Benjamin Netanyahu would likely return at the head of a far more homogenous, and rightist, government, backed by a public that overwhelmingly shares Mr Sharon's public contempt for Mr Arafat.
Whether or not Mr Sharon's Palestinian Authority-Taliban analogy has won over the Americans, the parallels are clearly far from complete. And perhaps the most important difference, in contrast to the recent celebratory scenes from "liberated" Afghanistan, is that there will no widespread relief and rejoicing among "ordinary" Palestinians should Mr Arafat's regime be broken.
Far from sharing the Israeli government's anger with Mr Arafat the terror-sponsor, a substantial proportion of the Palestinian public regards him as having been overly conciliatory to Mr Sharon at a time when settlements are quietly expanding and the transfer of occupied territory to Palestinian control has long since stalled.
Opinion polls show Palestinians evenly split between support for the Islamists and for Mr Arafat's Fatah faction of the PLO. And Fatah, sensitive to that public mood, has become increasingly involved in recent months in Intifada violence.
As Israel, with the US at its side, pounds away at Palestinian Authority targets, it does so in the knowledge that the expedited demise of Mr Arafat would not automatically usher in an improved chance of peace-making.
David Horovitz is a Jerusalem-based correspondent for The Irish Times