Ariel Sharon, the Israeli Prime Minister, has made two dramatic speeches in the past few days. On October 4th, in an address he had drafted himself after a Palestinian gunman shot dead three Israelis at a bus station in northern Israel, Mr Sharon indicated that any partnership between Israel and Yasser Arafat's Palestinian Authority was at an end. From now on, he declared, Israel would "rely only on itself" to ensure the security of its citizens.
This past Tuesday, by contrast, Mr Sharon spoke in a markedly different tone. Highlighting his agreement in principle to Palestinian statehood, he offered, for the first time, to head the negotiations towards a permanent accord between Israel and a new Palestine and, also for the first time, sketched out some of his envisaged parameters for statehood.
The shift in tone was clearly a result of pressure from the United States, and from America's allies - including Britain and Ireland - in the coalition now committed to an assault on international terrorism. The message to Mr Sharon, from Washington and elsewhere, was that in the post-September 11th reality, Israel needed to show itself willing to contemplate far-reaching compromises to help secure a final accommodation with the Palestinians, or risk being perceived as an obstacle to peace, and to the coalition's Middle East interests.
The unprecedented assassination by Palestinians of Israeli cabinet minister Rehavam Ze'evy outside his Jerusalem hotel room yesterday morning changes that reality again, and the question now is whether Mr Sharon will be prepared to maintain the coalition-pleasing posture of moderation, or will revert to his earlier tougher stance.
The initial indications are that the tougher stance will prevail - and that, conscious of the risks this poses to Israel's long-term strategic alliance with the United States, Mr Sharon will now try to justify that stance by endeavouring to convey to Washington his assessment that Mr Arafat is an unreconstructed terrorist, who is merely pulling the wool over Western eyes in purporting to ally himself with the anti-terror assault.
The Prime Minister's first public remarks, to an emergency gathering of his ministers soon after news broke of the shooting in Jerusalem were that "nothing will be the same" - a presumed indication of plans for some kind of stepped-up Israeli military response.
His second public remarks, at a special mourning ceremony in the Israeli Knesset, were that Mr Arafat bore "full responsibility" for the assassination, since the Palestinian Authority leader had failed to "take any serious steps" to arrest alleged terrorists or make it difficult for them to operate.
Mr Sharon was well aware, of course, that the Palestinian Authority had been quick to issue a statement expressing sorrow at the killing of Mr Ze'evy, promising to track down those who were to blame, and calling for "an end to this vicious cycle of killing and violence." He was well aware, too, that the Popular Front for the Liberation of Palestine had taken responsibility for the assassination - which it described as revenge for Israel's killing, on August 27th, of its leader, Abu Ali Mustafa. Mr Mustafa died instantly when an Israeli helicopter fired a missile through the window of his Ramallah office.
But Mr Sharon - indeed ministers across the political spectrum, including those from the Foreign Minister, Shimon Peres's Labour Party - have been adamant that Mr Mustafa was personally and directly engaged in orchestrating attacks on Israeli civilian targets, including two car bombings in central Jerusalem.
The decision to eliminate him, the Israelis insist, was the continuation of a longstanding decision to "target" Intifada kingpins whom Mr Arafat was disinclined to arrest. So while the PFLP argued yesterday that its assassination of Mr Ze'evy was something of an "equivalent" act of violence, Israeli officials were standing by their assertion that Mr Mustafa was a terrorist, Mr Ze'evy a politician, and that it was the Palestinians, therefore, who had escalated the conflict.
That argument is unlikely to get a particularly receptive hearing in Washington or London. For months, the US and Britain have been expressing criticism of Israel's policy of targeted killings, and have rejected Mr Sharon's assertions that there is no difference between such hits and the current American-led effort to eliminate Osama bin Laden. Mr Sharon's frustration at what he sees as an American double standard, an apparent differentiation between terrorism that has hit the US and terrorism that has hit Israel, was one of the factors behind his explosive October 4th speech, in which he also accused the Bush Administration of gearing up to "sacrifice" Israel in order "to appease the Arabs."
The Israeli-Palestinian conflict now threatens to spiral out of control - with dire implications for the US-led assault on terror. It is hard to see moderate Arab states remaining supportive of the US if Israel now flexes military muscle.
The tragedy is that there does appear to be a recipe for ending the conflict. In essence, it involves reversing the spiral. The US and others in the anti-terror coalition, belatedly recognising how badly their own interests can be affected by ignoring this conflict, are now ready to intervene energetically, and are apparently ready to unveil a new blueprint for Palestinian statehood and peaceful co-existence.
If they can exert pressure on Mr Arafat, in the aftermath of yesterday's shooting, to begin a serious crackdown on Hamas, other Islamic extremists, and on Palestinian hardline groups such as the PFLP, which has always opposed co-existence with Israel, the Palestinian leader would not only win kudos from the Bush Administration, but he would also boost the moderate camp in Israel.
He would bring an end to Israel's targeted killings. And a genuine, continuing decline in Intifada confrontation would enable Israel to lift some of the restrictions on Palestinian movement, and other measures that are embittering ordinary Palestinians, which could gradually raise popular Palestinian support for an accommodation -- support that has withered as the Intifada has continued.
Yossi Beilin, the former Israeli justice minister and architect of the collapsed Oslo peace process, set out such a vision yesterday, asserting that "precisely at this moment," when the future looked so bleak, there was a real opportunity to reverse the grim cycle of events here. It took an inveterate optimist like Mr Beilin, however, to try and nurture that constructive glimmer.
Few others see any room at all for hope.
David Horovitz reports from Jerusalem for The Irish Times