Managing Egypt's revolution
The United States is trying to steer Egypt away from revolution towards evolution.
It is seeking a middle, managed course towards change.
It does not want simply to dump an ally of 30 years, one who has stood by the treaty with Israel which is of great importance to US Middle East policy.
But it is now signalling that President Hosni Mubarak's departure - if not now, then later - has to be part of that change.
You can see this in a shift of American language.
Last week, US Secretary of State Hillary Clinton said the Egyptian government was "stable and looking for ways to respond to the legitimate needs and interests of the Egyptian people".
End Quote Hillary Clinton US Secretary of State
We want to see this peaceful uprising on the part of the Egyptian people to demand their rights to be responded to in a very clear, unambiguous way by the government, and then a process of national dialogue that will lead to the changes that the Egyptian people seek and that they deserve”
But by Sunday, she was calling for "an orderly transition to a democratic government".
The question is now not whether Mr Mubarak should go, but when. A presidential election is due in September this year, so that could be a face-saving date. But it is too far off to placate the protesters.
At the same time, the word has also been sent to the Egyptian military to show restraint. The US has considerable leverage there.
It provides more than $1bn (£630m) worth of military aid to Egypt every year. The Egyptian army absolutely relies on US technology.
The tanks on the streets of Cairo are American-designed M1A1 Abrams, assembled in Egypt.
In the meantime, Washington wants the process to start.
This is what Mrs Clinton also said on Sunday: "We want to see this peaceful uprising on the part of the Egyptian people to demand their rights to be responded to in a very clear, unambiguous way by the government, and then a process of national dialogue that will lead to the changes that the Egyptian people seek and that they deserve."
However, she added: "Now, that will take time. It is unlikely to be done overnight without very grave consequences for everyone involved."Opposition's time
This means there should to be an interval during which an organised and broad-based opposition can emerge.
The last thing Washington wants is for the currently strongest opposition group, the Muslim Brotherhood, to acquire a position of political power - which would be part of the "grave consequences" Mrs Clinton alluded to.
It will be interesting to see if the US quietly rallies support for Mohamed ElBaradei, the former head of the UN nuclear agency, the International Atomic Energy Agency (IAEA). He is not charismatic, but he is available.
All this once again highlights the difficulties the US gets into with its autocratic allies.
In 1979, having backed the Shah of Iran for years, it urged reform and then forsook him.
He knew his time was up when the White House spokesman noted approvingly that the Shah had indicated he wanted to take a vacation. He never came back.
The Egyptian revolution has been quite different, more like the revolutions of Eastern Europe - which is why the US hopes it can be managed.