A massive stroke has felled Israeli Prime Minister Ariel Sharon. Recovery is uncertain, and most observers believe his political career is over regardless. The loss will be felt not only by Israel but also by Palestinians and the world. For all his shortcomings, Mr. Sharon has been a leader with a vision, capable of making -- and sticking with -- unpopular decisions. It is precisely that characteristic that is most needed in the Middle East today. It is, sadly, in ever shrinking supply.

Mr. Sharon suffered a minor stroke in late December. A small hole in his heart allowed a blood clot to travel from the heart and briefly block the flow of blood to part of the brain. It quickly dissolved and left no permanent damage. The prime minister resisted the release of his medical records, insisting that he was in good health. Doctors gave him anti-blood-clotting injections to prepare for surgery, scheduled for this month, to repair the hole in his heart.

That treatment may have helped cause the massive stroke that felled Mr. Sharon last week when he collapsed at his farm. Three rounds of emergency surgery left the prime minister in a medically induced coma, but it is unclear if he would emerge from the coma and what condition he would be in if he did.