The Aids epidemic and climate change could make the world more unstable over coming decades, according to a government analysis.

Thursday's warning came in a paper, published by the strategy unit at Number 10, addressing the challenges posed by fragile countries.

It warns that the risk of instability in many countries is expected to increase, especially as HIV/Aids and climate change impact on already unstable countries.

Stronger national and regional governance, as well as declining rates of poverty, could act as a counter-veiling force, however.

Preventative action is needed to reduce international conflict and stem the toll of human suffering in unstable countries, adds the report.

High costs

It says that instability across the globe affects Britain's own security, stability, and prosperity.

"Increased conflict and state failure will impact on the UK directly, hampering efforts to tackle terrorism and organised crime, locking countries into poverty, stimulating refugee flows, and undermining the UK's energy security," the report states.

The analysis suggests that rebuilding failed and conflict ridden states is expensive and lengthy, and 50 per cent of countries fall back into conflict after five years.

It calls instead for scaled-up preventive action across the international community to help reduce the risk of conflict and political instability.

The report puts forward a package of priority policy initiatives which could make a significant impact over the next five years.

Tackling poverty

It argues that reducing poverty in Africa - one of the UK's priorities for 2005 - requires extra investment, more aid, better trade, and debt reduction. 

Four priority areas are highlighted for action: investment to help vulnerable countries' manage conflict; stronger regional support for governments committed to stability; a greater effort from all countries to help tackle global causes of instability; and an effective response to crises for when prevention fails.

The report suggests that successful prevention of international conflict will also require joined-up and strategic cooperation between different arms of government - diplomatic, development, military and policing.

It warns that the risk of instability in many countries is expected to increase over the coming decades, especially as HIV/Aids and climate change impact already unstable countries.