The 19th day of March and the armies of several countries are preparing their first strike. Using overwhelming military force, they plan to cow a dictator and allow the aspirations of his people to flower. The war, say the commanders of the armies, will be swift and decisive. The war, says the country's long-time leader, will be long and bloody. They both turn out to be right, for once the initial military mission is done the real task turns out to be hard, dirty and brutal.
That was Iraq in 2003. Eight years on to the day, US forces last week again went to war against an oil-rich Arab state whose long-time leader the West had previously been friends with. Last Saturday, French military aircraft struck targets in Libya, followed by a barrage of US and British missiles on Col Muammar Qaddafi's command-and-control centres. As with the invasion of Iraq, the easy part was bombing targets from the air. The hard part of the mission comes next.
But what is that mission? Originally, the alliance committed to protecting civilians from attacks by Col Qaddafi's forces. Already, cracks are beginning to show. The secretary general of the Arab League, Amr Moussa, has suggested the alliance may be exceeding its mandate. Barack Obama, the US president, is facing restive opposition at home. Turkey, a member of Nato, worries about the possibility of being drawn into a ground war.
The alliance is even divided about whether the people it is defending are a government or a group of plucky rebels: France has recognised the group of self-proclaimed leaders in Benghazi as the true representatives of Libya.
Cracks in the alliance, and cracking outside. Many have criticised the alliance for not thinking through its options, for going to war without a clear aim in mind. Yet in fact, the alliance almost took too long to decide. I wrote last week that time was running out for the Libyan rebels and called for rapid intervention in Libya, with the involvement of Arab troops. Nato is now in command of the skies above Libya, and Qatari and UAE fighter jets will join them; the speed of the mission was necessary and its Arab component vital. A week ago, troops loyal to Qaddafi were on the outskirts of Benghazi; now that city is safe from air attack.
That the alliance came about because of pressure from the GCC countries and due to a request from the Arab League for, in effect, a humanitarian intervention in another Arab country, is a tremendous sea change in Arab affairs. Swift intervention has put options on the table; it remains the right course of action.
That's the good news. The bad news is almost all the realistic future options are bad.
Speaking this week, Mr Obama said he saw the end result in Libya as "ultimately sweeping Qaddafi out of power".
"Our hope is that the first thing that can happen once we've cleared the space is that the rebels are able to start discussing how they organise themselves, how they articulate their aspirations for the Libyan people and create a legitimate government," he told the television network CNN.
That sounds like regime change, although his spokesman has insisted that regime change is not the goal. Yet it is clear that there can be no national government by the rebels without Mr Qaddafi going.
This tension lies at the heart of the alliance's future. Without Mr Qaddafi's departure, in some form, the rebels cannot assume control of the country. The bad news is Qaddafi isn't showing signs of going anywhere.
This leaves a few options, most of them bad.
The best among them is that Mr Qaddafi is removed from the scene, either because so many of his army and supporters change sides that his position becomes impossible and he leaves, or somehow he is killed.
But members of the alliance, wary of being seen to target heads of state without legal mandate, have said publicly that Mr Qaddafi isn't a target. In the coming days, that may change: one line of argument that could become more pressing if a long intervention looms will be that Mr Qaddafi, as head of an army that has targeted civilians, is himself a legitimate target.
The US secretary of state has suggested Qaddafi's supporters are putting out feelers for exile, yet thus far there is nowhere for him to go. By providing him with as few options as possible to manoeuvre, the alliance may be backing him into a corner from which he can only fight.
That fight may be long. The east of the country, where the rebels are based, is protected by the no-fly zone. But the rebels are poorly armed and untrained; they cannot attack the army that remains loyal to Mr Qaddafi. Without air cover from outside actors, the rebels would most likely have been crushed already. Even with air cover, they are unlikely to be able to march on Tripoli.
And even if they did, an assault on the capital by rebel troops would endanger civilians there, which could mean the military alliance finds itself enforcing a no-fly zone over Tripoli while civilians there are harmed.
Given the geography of the country, the looming likelihood is a stalemate, with the rebels controlling Benghazi and the east of the country and Qaddafi installed in Tripoli and the west. That stalemate could go on for a while, or descend into a bloody civil war. Although Obama has insisted that US troops would not be deployed in Libya, the US ambassador to the United Nations has said the current UN resolution would not exclude the United States from arming the rebels. That could be a prolonged process and would mean a no-fly zone would have to continue to be enforced, presaging an open-ended commitment for the alliance's army.
After all, the US invasion of Iraq in 2003 began many years earlier and was an extension of the war the US fought against Iraq in 1991. In the aftermath of that conflict, a no-fly zone was imposed on the northern and southern portions of Iraq. That no-fly zone lasted for years, and ending it was part of the calculation for the second Iraq war.
"This is not the end," declared Winston Churchill after the Allied victory at El Alamein in Egypt during the Second World War. "It is not even the beginning of the end. But it is, perhaps, the end of the beginning."
There is still a long road to change in Libya, with no end in sight. The alliance will be hoping that, after a week of air attacks, they at least have passed the beginning.