Image caption Poverty rates are 20% higher in countries hit by violence, so aid should target violence, the Bank says

The World Bank is recommending a major difference in the way aid is spent.

A quarter of the world's population live in states affected by conflict.

In a report released on Monday, the World Bank says that there should be far more focus on building stable government, and on justice and police, than on health and education.

The report says if there is not a major refocusing of aid in this direction, then other targets on poverty, health and education will not be reached.

There is far more spent on alleviating the effects of conflict than preventing it from breaking out, and conflicts tend to be repeated.

Ninety percent of recent civil wars occurred in countries that had already had a civil war in the last 30 years.

The report found that cycles of violence were hard to stop, for example in South Africa and Central America.

In Guatemala, twice as many people are dying now at the hands of criminals than died in the civil war in the 1980s.

Poverty rates are 20 percentage points higher in countries affected by violence, but up to now, the World Bank found, there had been too little focus on ending corruption or reforming state institutions and justice systems. For instance, reform of justice was not one of the Millennium Development Goals.

Police, not hospitals

The report's author Sarah Cliffe says this is the greatest development challenge facing the world.

"It's much easier for countries to get help with their militaries than it is with their police forces or justice systems, and much easier for them to get help with growth, health or education than it is with employment," she says.

"Our analysis would indicate that that should change."

A lot of this thinking is not new.

Britain is already refocusing its aid towards conflict states.

If other countries do the same it would mark a fundamental shift, where spending money on good police becomes a higher priority than good hospitals or schools.