All right, it would have been better if he had not been struck down. His massive personality enabled him to redraw the centre ground of Israeli politics, and to strike deals with Washington and Palestinian leaders.

In the feverishly personalised state of the region’s politics, these deals are still pushed through by individuals, not parties, or Cabinets, or voters. Change the people and you change the deal.

But any vision that depends on the health of a single person is fragile. To rest so many hopes on one person who is 77, vastly overweight and has had a stroke is to deny reality. Something that was so likely to happen cannot be called a catastrophe, let alone a surprise.

When Sharon announced the creation of his new Kadima party, many accepted his boast that if he had helped do it once with Likud he could do it again. But that is doggedly to ignore that 32 years had passed in between.

For all the distraught cries yesterday of “Arik, not now”, his illness could have come at many worse times. Just seven months ago and we might have lost the Gaza withdrawal, which has done more to make a “two-state solution” a reality than any other move.

But now? Yes, it throws the outcome of the March elections into doubt; as head of Kadima, he had been expected to win. There are tricky decisions to be taken before then; most pressing is whether to allow Palestinians in Jerusalem to vote in the Palestinian elections this month.

Mahmoud Abbas, the Palestinian leader, would no doubt love to provoke any interim prime minister into refusing these residents the vote, as a pretext for calling off elections in which the militant Islamic group Hamas is expected to do well. That is the first tough decision facing Sharon’s successor.

Yet Sharon had kept his plans beyond March opaque: above all, how much of the West Bank he intended Israel to keep. Any successor will have to tread carefully. But it is hard to say that Israel has lost a great strategist when Sharon’s favourite tactic was to keep so many options wide open.

Many of his achievements will last, even the most recent. Kadima will probably survive; it has already attracted too many powerful voices to disappear in the dust. Its policies may not be clear but its decision to plant itself in the centre certainly is.

Ehud Olmert, a contender to lead Kadima, does not have Sharon’s charisma. It remains to be seen whether he has the strength of character to force through deals. But he is intelligent and capable. Even if Kadima, under his stewardship, would be less likely to lead a coalition, it might still do well enough to hold an important position within one.

The effect of Sharon’s exit may be to bring Binyamin Netanyahu, a likely leader of the next government, towards the centre. He has lost the opponent driving him further right.

Any successor to Sharon as prime minister will be a civilian. It will be good for Israel to put the era of leadership by generals behind it.

In depriving some Arab leaders, and many Palestinians, of their bogeyman, Sharon’s incapacity helps to force them to confront their own responsibility in fostering a viable Palestinian state — as the chaos in Gaza must also do.

It is inevitable that Israel and the region are shaken by Sharon’s sudden exit. But his failure to permit the emergence of an obvious successor was part of the problem, however great his strengths. There are worse predicaments than the need suddenly to fill a vacuum.

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