RIYADH, Saudi Arabia â Saudi Arabia's ex-ambassador to Washington said former President George W. Bush left a "sickening legacy" in the Middle East and warned that U.S.-Saudi relations would be at risk if the Obama administration doesn't change America's policy in the region. Prince Turki al-Faisal's unusually tough words were the latest blunt assessment by the Saudi royal family that prospects for Arab-Israeli peace are growing dim unless dramatic policy changes are made. Turki said he strongly promoted the Arab-Israeli peace process in his decades as a public servant. But after Israel's three-week assault in the Gaza Strip, the prince said, "these pleas for optimism and co-operation now seem a distant memory," he said in a Financial Times op-ed published Friday. The kingdom has resisted calls for a holy war against Israel, "but every day this restraint becomes more difficult to maintain," he added. The comments followed a warning from King Abdullah on Monday that his 2002 Arab-Israeli peace initiative won't remain on the table forever. "America is not innocent in this calamity," said Turki, who is the chairman of the King Faisal Center for Research and Islamic Studies in Riyadh. "Not only has the Bush administration left a sickening legacy in the region, but it has also, through an arrogant attitude about the butchery in Gaza, contributed to the slaughter of innocents." The impassioned comments are a departure from the oil-rich kingdom's normally diplomatic rhetoric toward the U.S., its longtime ally. The Bush family has had strong ties with the Saudi royal family, and Turki's harsh public comments about Bush were rare. Analysts say the king had to send a clear message after Israel's assault in Gaza left almost 1,300 Palestinians dead. A cease-fire between Israel and Hamas, which rules Gaza, was in its sixth day Saturday. "The tone had to change to confront the violence and extremism on the other side," said Dawood al-Shirian, a prominent Saudi columnist. Turki also urged President Barack Obama to "strongly promote the Abdullah peace initiative." The 2002 initiative, relaunched in March 2007, offers Israel collective Arab recognition in exchange for withdrawal from territory it occupied in the 1967 war, the establishment of a Palestinian state with east Jerusalem as its capital and a just solution to the Palestinian refugee problem. Israel has said the initiative could be a starting point for discussion. The Saudi prince said Obama must address the Gaza crisis, including condemning both Hamas' rocket firing and Israel's "atrocities against Palestinians" and supporting a U.N. resolution to that effect. Israel says it launched the offensive to stop Hamas militants from firing rockets into Israel. During his first week in office, Obama struck themes familiar from the Bush administration. He backed Israel's right to defend itself, criticized rocket attacks on Israel by Hamas, lamented civilian deaths in Gaza and favored an international effort to develop a durable cease-fire. On Friday, Abdullah discussed the Mideast in a telephone call with Obama, the official Saudi Press Agency reported. No details were available.