By Tom Carver BBC Washington correspondent

After the most recent events in Israel and Gaza, reviving any sort of Middle East peace process is going to be very tough.

At a minimum, the Americans need the two sides to be willing to sit round a table together.

The Americans can encourage, flatter and cajole, but they cannot force them to take their seats

Before the weekend's suicide bomb attacks in Israel, the Americans saw Israeli Prime Minister Ariel Sharon as the sticking-point.

They were going to use his visit to Washington to urge him to drop his insistence on seven days of "absolute quiet".

But with scores of Israelis dead and injured, the Americans have to tread more carefully.

Awkward position

The administration has not even issued its usual public appeal to Israel to show restraint.

Officials are keenly aware that they can hardly tell the Israelis not to go after terrorists when that is precisely what the Americans are doing in Afghanistan.

The US is waging its own declared war against terrorism

And many of the hawks in the administration sympathise strongly with Israel's determination to crack down hard.

"The only way to defend against terrorists is to go after the terrorists," said US Defence Secretary Donald Rumsfeld when asked what Israel should do.

Even Secretary of State Colin Powell, normally the voice of evenhandedness and caution, said: "America is not going to tell Ariel Sharon not to defend his nation."

And so the American spotlight is now falling heavily on Yasser Arafat.

'Tall order'

The leader of the Palestinian Authority has been told not only to arrest those responsible for these attacks, but to dismantle the training camps and the infrastructures of groups like Hamas and Islamic Jihad.

It is a tall order and the Americans have made these demands before.

There is strong emotional pressure on the US at home

Each time Yasser Arafat has stopped short, reluctant to confront his hard-liners head on.

The Americans are trying to turn these attacks into what Colin Powell calls a "moment of truth" in the hope of jolting Mr Arafat into going further than he has ever gone before.

The Israeli Government is convinced Mr Arafat could turn off the Intifada tap tomorrow if he wanted to.

That may be true, but the Israeli prime minister has not shown much interest in accomodation either.

Americans suspect his seven-day demand is a convenient way of avoiding having to make difficult concessions.

Limits

The American envoy, General Anthony Zinni, has promised not to leave the Middle East until he has got an end to the violence, but he has been temporarily swept aside by events.

At the end of the day, the Americans' whip of influence is limited

Last year, President Bill Clinton gambled his reputation on securing a Final Status Agreement - and failed.

Bush officials were watching closely and are not going to risk their political lives on that kind of all-or-nothing strategy.

And at the end of the day, the Americans' whip of influence is limited.

Sooner or later, the two sides will have to sit down at the negotiating table.

The Americans can encourage, flatter and cajole, but they cannot force them to take their seats, especially in this present climate.