Last week Alex Marshall made the argument that the noughties (he calls them the aughts) was the decade that infrastructure came back onto the agenda, in the US, and around the world. He's right; after a political economy revolution in the eighties and a digital revolution in the nineties, it was about time we thought about our physical needs again.
But looking from a developing-world perspective, the neglect of infrastructure is not a question of a few decades. Stretching back centuries, colonial masters in many parts of the world selectively invested infrastructure and planning efforts only in the European centres of their cities.
They chose to deny adequate water and sanitation infrastructure in the native districts to save money, to control their subject populations, and out of simple racial prejudice. Many of today's largest and most persistent slum settlements were established in this period.
The institution of the two-tier city carried over into the post-colonial world, where urban elites enjoyed the power yielded to them by an economically and politically suppressed poor.
Combined with the weak bureaucracies often left behind by departing colonialists, many local leaders show little real interest in mandating sufficient wages to the poor or collecting sufficient taxes to create an economic base for universal infrastructure delivery.
The planning of infrastructure in many developing-world cities has since been led by haphazard political opportunism, with infrastructure extended into favoured districts, corners cut elsewhere, and maintenance of the systems entirely forgotten.
It has been a struggle also to convince populist political forces to invest money in pipes hidden underground, rather than on highly visible public buildings and transport systems upon which politicial patrons' names and faces can be festooned.
So it would be wrong to hope that over a century of neglect can be undone by two decades of faddish infrastructure investment now. For this recent push to truly overcome the world's water and sanitation crisis, the projects being built today must be accompanied by hard economic programmes to improve the wages of the urban poor, and the tax base that they represent, so that what is built today is systematically maintained and expanded in the future, in line with urban population growth.
In many cities, even the idea that all people living in cities are deserving of infrastructure delivery has not yet taken root.
Transforming this into practice will be the work of generations. We will have to hope that our leaders have the concentration span to focus on this problem long enough.