Barack Obama's chances of making a fresh start in US relations with the Muslim world, and the Middle East in particular, appear to diminish with each new wave of Israeli attacks on Palestinian targets in Gaza. That seems hardly fair, given the president-elect does not take office until January 20. But foreign wars don't wait for Washington inaugurations.

Obama has remained wholly silent during the Gaza crisis. His aides say he is following established protocol that the US has only one president at a time. Hillary Clinton, his designated secretary of state, and Joe Biden, the vice-president-elect and foreign policy expert, have also been uncharacteristically taciturn on the subject.

But evidence is mounting that Obama is already losing ground among key Arab and Muslim audiences that cannot understand why, given his promise of change, he has not spoken out. Arab commentators and editorialists say there is growing disappointment at Obama's detachment - and that his failure to distance himself from George Bush's strongly pro-Israeli stance is encouraging the belief that he either shares Bush's bias or simply does not care.

The Al-Jazeera satellite television station recently broadcast footage of Obama on holiday in Hawaii, wearing shorts and playing golf, juxtaposed with scenes of bloodshed and mayhem in Gaza. Its report criticising "the deafening silence from the Obama team" suggested Obama is losing a battle of perceptions among Muslims that he may not realise has even begun.

"People recall his campaign slogan of change and hoped that it would apply to the Palestinian situation," Jordanian analyst Labib Kamhawi told Liz Sly of the Chicago Tribune. "So they look at his silence as a negative sign. They think he is condoning what happened in Gaza because he's not expressing any opinion."

Regional critics claim Obama is happy to break his pre-inauguration "no comment" rule on international issues when it suits him. They note his swift condemnation of November's terrorist attacks in Mumbai. Obama has also made frequent policy statements on mitigating the impact of the global credit crunch.

Obama's absence from the fray is also allowing hostile voices to exploit the vacuum. "It would appear that the president-elect has no intention of getting involved in the Gaza crisis," Iran's Resalat newspaper commented sourly. "His stances and viewpoints suggest he will follow the path taken by previous American presidents... Obama, too, will pursue policies that support the Zionist aggressions."

Whether Obama, when he does eventually engage, can successfully elucidate an Israel-Palestine policy that is substantively different from that of Bush-Cheney is wholly uncertain at present.

To maintain the hardline US posture of placing the blame for all current troubles squarely on Hamas, to the extent of repeatedly blocking limited UN security council ceasefire moves, would be to end all realistic hopes of winning back Arab opinion - and could have negative, knock-on consequences for US interests in Iraq, Afghanistan and the Gulf.

Yet if Obama were to take a tougher (some would say more balanced) line with Israel, for example by demanding a permanent end to its blockade of Gaza, or by opening a path to talks with Hamas, he risks provoking a rightwing backlash in Israel, giving encouragement to Israel's enemies, and losing support at home for little political advantage.

A recent Pew Research Centre survey, for example, showed how different are US perspectives to those of Europe and the Middle East. Americans placed "finding a solution to the Israel-Palestine conflict" at the bottom of a 12-issue list of foreign policy concerns, the poll found. And foreign policy is in any case of scant consequence to a large majority of US voters primarily worried about the economy, jobs and savings.

On the campaign trail, Obama (like Clinton) was broadly supportive of Israel and specifically condemnatory of Hamas. But at the same time, he held out the prospect of radical change in western relations with Muslims everywhere, promising to make a definitive policy speech in a "major Islamic forum" within 100 days of taking office.

"I will make clear that we are not at war with Islam, that we will stand with those who are willing to stand up for their future, and that we need their effort to defeat the prophets of hate and violence," he said.

As the Gaza casualty headcount goes up and Obama keeps his head down, those sentiments are beginning to sound a little hollow. The danger is that when he finally peers over the parapet on January 21, the battle of perceptions may already be half-lost.