In politics, optimism is important. In W, Oliver Stone's biopic of George W Bush, he neatly reimagines the White House war room in the months before the 2003 invasion of Iraq. Scott Glenn, playing the US defence secretary, Donald Rumsfeld, argues that a small force could easily topple Saddam Hussein.
"Don't you think the Gulf war days are long gone?" he asks. "Do we really need half a million men to knock off a tinpot dictator with a ragtag army?" That was the best-case scenario that became the United States' optimistic best-laid plan.
Optimism is also important in North Africa, even if it is hard to be optimistic as Libya's leader wages war on his own people. Delirious talk of an Arab Spring may not eventually be realised, but the worst expectations will almost certainly be confounded.
As I wrote last week, North Africa in 2011 is not eastern Europe in 1989. The region is of such immense strategic importance that great powers within and without the region will attempt to influence the final result. The chips will doubtless fall differently in different countries, but the model that Tunisia and especially Egypt finally take will be vital.
Given the inevitable political jockeying now going on, does it make sense to be optimistic about what comes next in North Africa? In Libya, the country could still tip into an abyss. In Egypt, the army is still in charge. In Tunisia, protesters are still camped on the streets of the capital, urging more rapid change.
That change has yet to be defined. A perpetuation of army rule, another autocrat, a flawed democracy: all are possible. Some are even probable.
A realist might say the best outcome for now is a period of experimental democracy, allowing time for different factions to form and organise. But that might leave institutions vulnerable to Islamist opponents, who, in Tunisia and Egypt, are the best organised political factions.
It is this element of a possible democratic future that most worries Europe and especially the United States. What works for American values may not work for US interests and the nagging fear of Islamists coming to power and upending the carefully managed order of the region remains. Having watched one US ally toppled by the people, Washington is now concerned that the people might disrupt its whole regional strategy.
But that fear is overdone, the result of a curious symbiosis between what the United States fears and the nightmare that allies such as Hosni Mubarak promoted, pushing their iron grip as the best defence against an Islamist takeover.
The reality is rather different. North Africa's Islamist movements have long recognised the futility of trying to impose Islamic rule. Whatever the history of the Muslim Brotherhood in Egypt and Al Nahda in Tunisia, both have thrown their weight behind a return to a democratic process.
One of the first pronouncements made by Rachid Ghannouchi, Al Nahda's once-exiled leader, on his return to Tunisian soil was to rule out a bid for the presidency by his movement. The Muslim Brotherhood in Egypt has made a similar declaration, explicitly rejecting a religious state for Egypt.
That may suggest caution or even stealth on the part of these movements. More likely, the decision reflects an understanding that Egyptian and Tunisian societies are not willing to accept Islamist-dominated governments. That might change, but it is unlikely the more radical Islamist fringe could ever persuade large numbers of North African society. As much as Islamists in the Middle East in recent years have spoken the language of religion, it is pragmatism that has marked their politics.
Indeed, optimism about democracy and its possible practitioners should chiefly come from the fact that power will probably mellow the Islamists: the nature of politics is compromise after all. Islamists who have been allowed to shout from the sidelines about women's morality will find themselves facing fewer nodding heads when they have to describe the details of their tax policy.
Moreover, the region's natural model for Egypt is Turkey, a big country with a hefty population and a history of leading the region. And there the Islamism of the Justice and Development Party has brought the country strong returns in nine years of power: a fast-growing economy, an independent foreign policy and a stronger voice in negotiating with the European Union.
Are there reasons to fear a theocratic government such as Iran on the shores of the Mediterranean? Yes, but there is more reason to be optimistic about another Turkey.
There is, however, a greater danger for the region than developing democracies. There remains the potential for chaos, either from social unrest such as the strikes that paralysed Egypt for weeks, or from civil war, such as that now threatening Libya.
Given the significant social and economic challenges facing North Africa, it is not inconceivable that political wrangling will bring only a succession of weak and unstable governments, forming and falling, with no one able to deliver social order and steady economic progress.
In the Middle East, that was the set of circumstances that characterised Syria in its post-independence years. The Syrians had barely won independence from the French before their first government was overthrown in a coup. The plotters were themselves overthrown a few months later. This instability continued for nearly two decades, with governments, wars and coups plaguing the country. The state of uncertainty was finally resolved by the accession of the Baath Party, consolidated by Hafez al Assad in 1970. His fearsome rule - now headed by his son - remains in place.
Yet the danger today is not that a secular strongman from the army would take over, as in the 1970s. Rather it is that a radical fringe might seize power and we will be gifted not with Syria after independence, but Afghanistan under the Taliban. There, the fighting between rival factions in Afghanistan that followed the Soviet withdrawal in 1989 consumed the country for years with Taliban rule initially providing some stability, though at a significant cost.
Given North Africa's position and importance, such a scenario might seem unlikely. But until a few weeks ago, western allies such as Mubarak appeared unshakeable.
There is a small lesson to be learnt from what followed the meeting in the war room below the White House in 2003. Iraq didn't unravel because US troops failed to unseat Saddam Hussein; it unravelled because no one sufficiently prepared for the aftermath. Optimism, as the Americans found in Iraq, can't save you if you don't plan.
That's where the international community - especially the Arab League, which has been refreshingly proactive over the Libyan crisis - needs to focus its efforts.
The direction North Africa takes is not yet set. What follows may not be the stuff of Washington's nightmares, but it might also not be the stuff of Tahrir Square's dreams. North Africa's neighbours should expect the best possible outcome for the people of the region. But they must plan for the worst.