PAUL Rogers, Peace Studies professor at Bradford University, has a new book out – Irregular War – Isis and the new threat from the Margins - and three facts grabbed my attention.

The first is that three quarters of the world population never flies. Second is the staggering sum already spent on the unsuccessful War on Terror since 2001 - three thousand billion dollars. It looks even worse in numbers - $3,000,000,000,000.

He then quoted a British geography professor who, in 1970, anticipated the future as a 'crowded glowering planet of massive inequalities of wealth buttressed by stark force and endlessly threatened by desperate men in the global ghettoes'.

Since then the world population has doubled to well over seven billion – so that's the crowded planet.

Because the industrial west's economic outlook is based on growth and the free market, with a minimum government intervention, it results in around 85 per cent of the world's wealth being owned by only 10 percent of the population – there's the massive inequalities of wealth.

The stark force is that astronomical sum spent on four unsuccessful recent wars, in Afghanistan, Iraq, Libya and Syria – the latter still continuing but now just from the air.

While Isis has grabbed the recent headlines it's only one of the threats that have arisen from discord and disruption throughout the world, some political, others economic or religious, in countries as far apart as Peru, Mexico, Spain, Nigeria, India, Sri Lanka and the Middle East. Add to these a billion hungry people and there's the global ghettoes.

The problem will continue to deteriorate as now the world's much smaller due to the speed of communication and instant news to all corners, courtesy of satellites and phones. Those with less now know what they're missing, and they want it.

Add to this all the damage to the environment causing an increasing release of CO2 and the imminent escape of methane producing significant climate instability and change. Those living at the margins will not only to have to move to escape famine, as happened in Syria, but the inevitable sea level rise means millions more seeking somewhere dry.

This challenge is a problem as the way forward isn't attractive to democratic politicians who have to sell it to an uninformed and self interested electorate every five years. However the solution is clear; commit at least half that monstrous military expenditure and develop renewable energy now, with an international grid, and spend much of the rest in the areas at risk of famine.

The alternative is unlimited millions looking for a new home – and we already refuse to cope with a much smaller number.