Communities need to be persuaded that the years before the line opens are not just a period of cost, disruption and blight but also one of work and opportunity.
As heavily armed soldiers continued rolling into the city in armoured vehicles on Tuesday, embattled authorities in Baltimore were struggling to control a growing crisis in their city, long notorious for urban blight and accusations of police brutality.
The corporate world is lobbying for an accelerated timetable with warnings that a protracted period of uncertainty will create an investment blight as companies suspend decisions until they know whether the UK is staying within the EU or heading for the exit.
The latest violence along one of Belfast's many sectarian faultlines highlights the divisions that still blight Northern Ireland despite the 20-year-old IRA and loyalist ceasefires and the power sharing administration in place since 2007.
Dan McLean, director at Crohn's and Colitis UK, says, "For people with a chronic bowel or bladder condition, not being able to find or access a public toilet can be a blight on life and sometimes stop people going out altogether".
For whatever the establishment now is, the idea of a black, British star transmitting an embittered, alienated slang that graphically illustrates urban blight, that draws unnerving attention to a tense, endlessly fracturing racial divide, is deeply unwelcome.
Today, its sceptre and crown have fallen down and, in a phase of cynical destruction masquerading as "development", Mumbai has become a metaphor for urban blight.
For example, the US "food stamps" program limits the things that can be bought, but it still attracts the same criticism from the same type of people who think welfare is a blight.
On the minus side, one can see the first inklings of the tendency to pad things out which came to blight some of his later mainstream work; Banks's fertile imagination meant that he could improvise very easily – Prentice's brother's standup comedy routines feel distinctly superfluous.
Yet Mr Blair, in this self-promoted "keynote speech", delivered to a small audience of investors and journalists, suggested no new cure for the blight other than "an international programme to eradicate religious intolerance".
