International bodies produce decisions without any authority to compel their members. How they do it depends almost entirely on the voting rule written into their founding treaty.
Consensus is not the same as unanimity
Many bodies operate by consensus, meaning a decision is adopted if no member formally objects. A member with reservations can allow it to pass without endorsing it.
This produces broader agreement than voting would, because it permits participation without approval, and it also produces vaguer text since objections are resolved by removing specificity.
The practical effect is that consensus bodies generate documents everyone can accept and few are bound by, which is a genuine outcome rather than a failure.
Weighted voting reflects contribution
Financial institutions typically allocate votes according to capital subscribed, so influence tracks the money a member has committed rather than its population or membership status.
This makes decisions predictable and makes reform difficult, since revising the weights requires the agreement of the members whose weight would fall.
Periodic reviews adjust the allocation to reflect changed economic size, and those reviews are among the most contested proceedings such institutions conduct.
Vetoes freeze rather than decide
Where any member can block, the body cannot act against the interests of a permanent member, which is a design choice made to keep major powers inside the institution.
The alternative was an organisation those states would leave, which had been the fate of earlier attempts, so the veto was accepted as a price of participation.
Business consequently shifts to bodies without the constraint, or to informal groupings, which is why deadlock in one forum produces activity in another.
Enforcement depends on member action
Almost no international body has its own enforcement capacity. Compliance is produced by members implementing decisions through their own legal systems.
Where implementation is slow or partial, the organisation can document non-compliance but generally cannot remedy it, which is why reporting mechanisms matter so much.
Reputational and reciprocal pressure does real work here, since states that ignore obligations find their own claims discounted in later negotiations.
Secretariats shape outcomes quietly
Permanent staff draft the texts, set agendas, prepare analysis and mediate between delegations, which gives them influence that no voting rule describes.
A skilled secretariat can construct a compromise that delegations would not have reached independently, by finding wording that satisfies each side's core requirement.
This is why appointments to lead such bodies are negotiated intensively despite the office holding no formal power to decide anything.