To be clear, neither the World Bank nor the IMF can replace the United Nations, though they were founded originally under the aegis of the institution. Their job is to provide economic policy advice and development finance rather than to broker settlements between warring powers.
However, by providing an umbrella at their annual meetings for peer-to-peer or leader-to-leader dialogue among nations with very different polities and cultures, they do offer an opportunity for very diverse nations to better appreciate the consequences of their unilateral actions on the broader global economy.
Running the world is a job for consensus-building, and while we do not yet have anything approaching world governance, the fact is that we are “all in it together” when it comes to global interdependence. The foreign policies of major powers reverberate internationally and should not be undertaken unilaterally.
This has perhaps never been so apparent, as the impact of the US-Israel war on Iran becomes clearer every day, despite an announced ceasefire. From a geopolitical, economic, financial and logistical standpoint, their combined assault looks more like the work of bungling amateurs than competent professionals.