When they first met as United States president and Israeli prime minister, George W. Bush made clear to Ariel Sharon he would not follow in the footsteps of his father.

The first President Bush had been tough on Israel, especially the Israeli settlements in occupied lands that Mr. Sharon had helped develop. But over tea in the Oval Office that day in March 2001 — six months before the Sept. 11 attacks tightened their bond — the new president signaled a strong predisposition to support Israel.

“He told Sharon in that first meeting that I’ll use force to protect Israel, which was kind of a shock to everybody,” said one person present, given anonymity to speak about a private conversation. “It was like, ‘Whoa, where did that come from?’ “