By Jonathan Beale
BBC News, Washington
This is no courtesy visit by Condoleezza Rice. President Bush has sent his secretary of state to the region at what he views as a critically important time.
In Palestinian leader Mahmoud Abbas, the US administration sees its best chance of helping create a lasting settlement.
The focus right now is on Israel's planned withdrawal from Gaza in August - the first difficult step on that path to peace.
The US still has a long way to go to bridge the gaps
Ms Rice will meet both Israeli Prime Minister Ariel Sharon and Mr Abbas to ensure everything is going according to plan.
She has already assigned US Army General "Kip" Ward to help the Palestinians reform their security services - vital if militant groups are to be kept under control.
There is also the promise of $350 million to help improve the lives of Palestinians - essential for the people to see their efforts are being rewarded.
And more money may be on its way in the form of an international aid package to help the Palestinians.
The secretary of state then moves on to visit three of the closest US Arab allies - Jordan, Egypt and Saudi Arabia.
Before she left Washington, Ms Rice said: "I hope to talk with all these nations about the changes that are sweeping the region and about their responsibilities as very central members of the Arab world to promote change."
In other words, she is going to tell them to embrace democracy.
As always, the difficulty is how far to push that message.
After all, the US wants these allies to continue helping in its "war on terror" and to promote stability in the region.
The US has been instrumental in persuading Egyptian President Hosni Mubarak to open up elections.
But senior American political figures - such as the former US Secretary of State Madeleine Albright - warn that the presidential contest could turn out to be a sham.
Egypt's opposition complain that the new rules are too restrictive.
In her recent visit to the region, the First Lady, Laura Bush, praised President Mubarak for this "bold and wise step".
Condoleezza Rice's praise may be more muted with the warning that he has still not done enough.
On her return journey the secretary of state will stop off in Brussels for an international conference aimed at boosting support for the Iraqi interim government.
The conference has been co-sponsored by the European Union and will include Iraq's neighbours.
Washington wants to work with Europe to rebuild Iraq
The fact that this conference is taking place in Brussels is at least a sign that the US and Europe are getting over past differences.
Washington wants others to help share the burden of rebuilding Iraq.
Public support for the US mission in Iraq appears to be slipping.
Condoleezza Rice will hope that this conference will send a message of solidarity not just to Iraq, but also to the American people.
Ms Rice will be working to Britain's agenda for her meeting in London of the G8 foreign ministers.
Though the US has largely signed up to Tony Blair's plans on African debt relief, it is still resisting the appeal to double its aid budget.
America is even more hostile to any proposals on tackling climate change that would lead to new targets to cut emissions.
London may seem like the easiest stop, but it will still test Condoleezza Rice's powers of diplomacy after an already gruelling week.