The speed of the collapse of the Assad regime in Syria is giving us a real-time insight into the dilemmas of foreign policy.
The solid becoming fluid in the blink of an eye, and a whole array of awkward questions being posed.
A dictator flees, his regime collapses and Foreign Secretary David Lammy addresses the Commons, telling MPs that Assad is a "monster," a "butcher" a "drug dealer" and a "rat".
But things are moving quickly.
When asked whether the UK would be suspending asylum applications from Syria, Lammy indicated that he didn't know.
He didn't know that his cabinet colleague, Home Secretary Yvette Cooper, was saying, at pretty much exactly that moment, that they were being suspended.
In the year to September, the fifth largest number of asylum claims by nationality came from Syrians and nearly every claim - 99% - were granted.
But the government is now pausing applications, alongside France, Germany and others.
Why?
The main reason is that the vast majority of people applying for asylum from Syria were doing so, they said, because they were fleeing the Assad regime.
That regime has now gone and therefore so has, on the face of it, the central case being made in most applications.
The other reason, described as much less significant in numerical terms but still a potential cause for concern on security grounds, is Syrians associated with the failed regime themselves now trying to claim asylum.
Figures in government are now also contemplating the prospect that some Syrians in the UK may now want to return to their home country.