Ariel Sharon's nickname is "The Bulldozer."

The nickname perfectly captures the man in terms of girth and psychological disposition — unstoppable in shoving aside opposition and pursuing his goals.

So it's no surprise that Israelis are in shock over the massive stroke that felled Sharon on Wednesday. What is surprising is the panic his stroke evokes not just among right-wing supporters but across the entire Israeli political spectrum.

"I'm terrified," says Lily Galili, a well-known correspondent for the liberal Israeli paper Ha'aretz. "It's very sad to realize how dependent we became on one person ... it's scary."

Sharon's fall also sows fear among many Palestinians who despise him but now can't foresee whom they will deal with. "We're uncertain where the Israelis are going to go with the end of the Sharon era," Palestinian leader Nabil Shaath told CNN.

And Sharon's stroke unnerves the Bush administration, which hinged its Mideast peace policy on his ideas. His exit leaves U.S. policy adrift.

Amid the growing uncertainties of the region, Sharon was the one leader who seemed to know where he was going, even if one disagreed with the direction. This mountainous man moved inexorably forward as the rest of the Mideast seemed to be spinning out of control.

Sharon marched ahead despite political and military setbacks that would have cashiered other politicians. He was a gambler whose risks often backfired. In 1982, his political career seemed finished after an Israeli commission found him blameworthy for the massacre of Palestinian refugees in Beirut following Israel's invasion of Lebanon. Yet he managed to rise again.

Israeli voters made him prime minister in 2001 after Palestinians rejected peace proposals and turned to violence. I interviewed voters in the liberal German Colony neighborhood of Jerusalem who whispered — as if ashamed to say it out loud — that they were voting for Sharon. Afraid of Palestinian shells falling on Jerusalem, these voters picked a tough guy they distrusted in hopes that he would quash the violence and they could get back to negotiations.

Sharon didn't believe in peace negotiations, however. He refused to deal with Palestinian leader Yasser Arafat and persuaded President Bush to do likewise. Meantime, he built a separation fence that zigzagged through the West Bank, to prevent infiltration by Palestinian bombers, and encouraged more Jewish settlement building on the West Bank in areas Israel wanted to keep.

After Arafat's death, pressure built for renewed talks with the Palestinians. Sharon needed to find a new direction. Unilateralism was his answer. He sought to draw Israel's new boundaries without negotiations. He pushed through a withdrawal from Gaza over the vehement objections of many from his Likud party. When those objections grew, he formed the Kadima Party, which was expected to dominate March elections.

But he never made clear his ultimate objectives for the West Bank. Perhaps he was simply maneuvering to buy time. Some believe he was ready to give up 90 percent of the West Bank. Others — myself included — think he envisioned a Palestinian mini-state made out of disconnected cantons linked by tunnels and bridges.

The chance of such a plan working was virtually zero, nor is a successor likely to achieve it. Palestinian moderates — riven by factions and unable to promise their public a future — are reeling. Gaza has collapsed into anarchy. Hamas Islamists will do well in forthcoming Palestinian elections. Violence will rise.

Yet Sharon's bulldozer personality created the sense that he knew where he was going. No other Israeli political leader had an alternative plan. So a majority of Israelis, Palestinian moderates and U.S. officials were drawn to this outsized figure who conveyed certainty in a region where that is a very rare commodity.

Now the Sharon era has ended, and it's hard to see a successor who can project the same sense of assurance.

No wonder many Israelis are scared.