The Bush administration was warned yesterday by former senior US diplomats that it is setting itself up for the failure of its Middle East peace summit by neglecting to lay the groundwork for a successful meeting of American, Israeli and Arab leaders.

The conference represents the Bush administration's most serious attempt to engage in Middle East peacemaking after seven years of violence between Israel and the Palestinians.

"The meeting as it stands now seems to be something of a gamble," the former diplomats warn the secretary of state, Condoleezza Rice, in a letter (pdf) obtained by the Guardian yesterday. "The chances of a perceived failure, even without a breakup, are profound."

The rare critique of US foreign policy was unusual both for its attempt to constructively influence the administration and because of the seniority of the former officials involved. They included Thomas Pickering, a former undersecretary of state for political affairs, Robert Pelletreau, a former assistant secretary of state for near eastern affairs, and Samuel Lewis, a former director of policy planning.

It was seen as a reflection of widespread frustration within an administration that resisted taking an active role in peacemaking for several years, and that now risks squandering its efforts because of poor planning. "This administration over the last six years has neglected this major issue ... It is only now, in the last year and a half of the administration, that I think they are realising there is an important role to play," Mr Pelletreau told the Guardian.

Critics accuse Ms Rice of abdicating an instrumental role for the administration and allowing the agenda to be set by the Israeli prime minister, Ehud Olmert, and the Palestinian leader, Mahmoud Abbas, who have been conducting regular meetings.

The writers urged the administration to reduce the burden of expectations on next month's summit, expected to be convened in Annapolis, Maryland, on November 15, by arranging a series of such meetings. The rationale behind that suggestion was to avoid a replay of the collapse of the Camp David summit during the waning months of the Clinton administration, which led to the September 2000 Palestinian uprising. The writers also argue that it would be easier to persuade Arab states, especially Saudi Arabia, to participate in a series of summits, rather than in an all-or-nothing meeting.

More controversially, the former officials urge the administration to drop its insistence on isolating Syria and Hamas. "Maximising the prospects for a successful meeting entails finding a way to deal with both Hamas and Syria," the letter says. It notes that Mr Abbas, the Palestinian president, has no control over Gaza and so would be vulnerable to attempts by Hamas to undermine any future deal. "Simply saying no to Hamas without planning for the consequences is a likely ticket to new problems," the letter says.

The diplomats go on to sketch out the contours of a future deal between Israel and the Palestinians, including an arrangement for sharing Jerusalem as the capital of two states.