Keynes said  that “In the long-run we are all dead.” But for people living in fragile states affected by violence, the short run can be deadly too.
The challenge is to balance swift action with long-term stability and security. The two must be carefully paced and sequenced if we are to make progress, both sooner and later.
Not by bricks alone.
Look at Haiti. Whoever emerges from the presidential elections  will be under huge pressure to get a lot done fast, from controlling the cholera epidemic and rebuilding homes to getting intimidating gangs off the streets and creating jobs.
We've been there many times before in fragile places the world over - whether they are emerging from the devastation of violent conflict, exacerbated in Haiti by the earthquake, or about to plunge into it. Neither national leaders nor the international community have been effective enough in responding to the pressures that lead to conflict or reignite its embers.
Speedy action to meet immediate needs is a good start but it is not enough on its own to solve what is perhaps our greatest development challenge -- giving a stake in the future to the 1.5 billion people who are forced to look on as the middle income countries power ahead, with many lower middle income states on their heels.
We must go further than meeting immediate needs and buttressing confidence with actions to consolidate early progress, when we make it. Much of the time, lack of local capacity and snail-paced international support mire us in the world of "might have been".
In those cases where timely action is taken, like Haiti, we are not good at embarking on the next, vital step in the process -- shoring up weak institutions without which no society can resist the economic, security and political pressures that bear down upon it.
This is a crucial piece of the puzzle and we must pay more attention to institution-building if we are to head off the conflicts that interrupt development.
Haiti's weak institutions are a long standing shortcoming that has left the country ill-equipped to deal with the many stresses that risk sparking another descent into chaos.
In practical terms this means focusing not just on immediate needs but on the longer term resilience of national institutions -- from government through civil society and the private sector. Acting in unison, with the right kind of international support, they can both prevent violence and contribute to long-term cures.
Our research  shows that the fastest reformers of the 20th century took some 20 years to attain levels of institutional solidity comparable to present day Ghana or Vietnam. There are no short-cuts. Unless today's fragile states embark on a sustained effort to build good enough institutions, their chances of following their 20th century role models are slim.
The next generation of citizens in fragile states will appreciate this long-term perspective even if in the longer run some of us won’t be around to share in their peace and prosperity.