Afghanistan held its landmark legislative elections this Sunday. Almost exactly four years after 9/11, and the invasion that followed, Afghanistan will have, for the first time in its history, a democratically elected constitutional government. That is something remarkable, and cause to celebrate - but only in the way that one cheers hopefully during a tough game at halftime.

Everything we know about democracy promotion and post-conflict reconstruction tells us that Afghanistan is far from out of the woods. Even after significant international intervention, many failed states remain unstable, or relapse into conflict and chaos. Remember Haiti? The United States invaded in 1994 and oversaw reconstruction and elections in 1995 and 2000, as international forces slowly withdrew. By 2004, U.S. and United Nations Forces were dispatched to the troubled island again. Haiti is not an outlier. World Bank studies show that countries coming out of civil war are forty percent likely to return to war within five years. It took one horrific hurricane to turn New Orleans to chaos. Imagine the effects of 25 years of war.

One of the main reasons failing countries continue to fail is economic. Economic recovery after war provides one of the best measures of the likelihood of long-term stability. International assistance can play a key role in jump-starting the economy and paying for basic government services, but it can take a generation to return to pre-war standards of living. The problem is that donor countries tend to be most generous in the first few years of the crisis - when local capacity to do something with those funds is limited. And just when the government starts to get on its feet - usually around the four-year mark - the assistance dries up.

The Afghan economy has seen remarkable growth rates over the last four years, but that is only half good. There is a truly free market now in Afghanistan - free from the rule of law. Much of the growth has come from the booming opium trade and other smuggling operations. While a strong economy is necessary to rebuild state and society, a criminal economy will necessarily destroy them both.

Politically, Afghanistan is getting its first taste of real elections - but it is far from being a stable democracy. There were more than 5,000 candidates in the legislative elections this Sunday, violence was relatively low, and turnout decent - all signs that political participation is blossoming. But nobody knows who will run the new parliament, or how it will function. It has no building and no staff. The only other parliament in Afghanistan's history, from 1965 to 1973, is widely blamed for increasing the polarization that led to civil war there. Since armed warlords still dominate many parts of the country, they will undoubtedly be strongly represented in the new legislature. As we have seen in places like Liberia and Serbia, post-conflict elections can produce quite undemocratic leaders.

What does this mean for Afghanistan? First, it means that the next four years will be as important there as the last four. Afghanistan's leaders, elected and otherwise, must put the cause of their nation before their factional, ethnic and venal interests. For our part, the United States and its allies must continue to support Afghanistan, financially and militarily, until it gets out of the danger zone. That means the same level of support for at least another four years.

Second, it means we have to shift our mentality there from short term to long term. If the United States has one overarching goal, it must be to build a legitimate Afghan state that is strong enough to survive and competent enough to deliver results. The Afghan police and legal system remain in shambles. Afghanistan's school system was rated the worst in the world last year by the United Nations Development Program. More international support needs to go to education, training a capable Afghan government, and supporting the rule of law.

Finally, it means something a little more intangible: continued political attention. If Afghanistan falls off the policy agenda in Washington, London and Berlin, the dangers that lurk there will prosper. Lagging reconstruction is already creating support for the ongoing Taliban insurgency. An unchecked opium trade keeps warlord armies well fed.

On this anniversary, we must remember the true cause of those grim attacks four years ago: Bin Laden and Al Qaeda had free reign of a failed state in chaos. We may not be able to find bin Laden, but we know where Afghanistan is located.