In the early 2030s, global demand for oil is expected to reach its peak — and then begin a long, irreversible decline. For Saudi Arabia and the United Arab Emirates, which produce cheaply and hold vast reserves, that moment represents a manageable adjustment. For Nigeria, Angola, Algeria and Iran, it could mean something closer to collapse. A report published Tuesday by the E3G thinktank, compiled over two years through scenario exercises involving more than 100 public servants and policy experts from around the world, identifies a dangerous gap between oil producers who are well-positioned to survive the energy transition and those who are not.

Mid-tier producers — countries that depend heavily on oil revenues to fund public services but lack the economic diversification or financial reserves to absorb a sudden shock — face the gravest risks. As global buyers shrink in number, the cheapest producers are likely to undercut the rest, leaving fragile states stranded with assets they can no longer profitably sell. The authors point to Venezuela as a live warning. Already suffering severe economic disintegration and a partial loss of governmental control, the country has been further destabilised by earthquakes, illustrating how quickly compounding crises can overwhelm a state that has no buffer.

"The transition becomes riskier for everyone when oil producers are left to adjust on their own, and oil markets left to manage themselves," said Beth Walker, co-author of the report. "Producer fragility becomes a global security risk." Critically, the report does not argue for slowing the shift away from fossil fuels — it argues that a slow but unmanaged transition can be just as destabilising as a rapid one.