During American President George Bush's early January visit to Jerusalem, Israel and the U.S. intend to announce a significant upgrading of diplomatic, economic and military ties, The Jerusalem Report has learned. As high-level teams from both sides work on the details, the precise form the upgrade will take is not yet clear. One of the ideas considered is the establishment of a formal military pact. Although this would signal a dramatic tightening of the strategic alliance between Israel and the U.S., it would also limit both countries' freedom to maneuver and reservations have been expressed on both sides. The idea was raised several weeks ago by Yoram Ben Zeev, the Foreign Ministry's outgoing director general for North America. In an internal memo, Ben Zeev argued forcefully for a formal pact with America, primarily on the grounds that it would help deter Iran from attacking Israel. He pointed out that under the terms of such a pact, the U.S. would consider any military attack on Israel an attack on America, and that this would appreciably strengthen Israel's deterrent posture. Ben Zeev noted that Israel had sought such a pact in the past, but, he argued, conditions in Washington had never been as favorable as they were now. Bush is one of the most supportive presidents Israel has ever known, and the current well-disposed Congress, especially in an election year, was sure to give the idea wall-to-wall backing, he wrote. But the idea ran into strong opposition among some Israeli government and defense officials who argue that a formal pact with the U.S. would tie Israel's hands: It would need American approval for any preemptive strike and that, they say, might weaken rather than enhance Israeli deterrence. Moreover, a formal pact with the U.S. could involve Israel in distant American wars. It is not clear where Prime Minister Ehud Olmert stands on the issue. The main American objection is that a formal pact with Israel could seriously limit U.S. flexibility in the conduct of foreign policy in the Arab and Muslim worlds. The upside for the U.S. is that it might induce Israel to go further in peacemaking with the Palestinians. Israeli and American officials discussed the pact proposal during the Clinton years and in the early years of the Bush presidency, but put the idea on hold after the American invasion of Iraq in 2003. Israeli officials refuse to confirm or deny whether it is now back on the agenda, but insist that "ways will be found to upgrade diplomatic, military and economic ties." The officials say the Bush visit will focus on three issues - energizing the Annapolis process with the Palestinians, upgrading U.S.-Israel ties and coordinating policy on Iran - and add that they are confident of its success. "All the parties - Americans, Israelis and Palestinians - have a strong interest in a visit that makes an impact," a senior official told The Report.