Usually the pain for one party is greater than the pain for the other, unless they are really peers of each other, in which case settlement free interconnections happen. However, if there isn't equal amounts of pain being felt on both sides, then normally the party with the more hurt tries to redress the issue.
Usually this imbalance in perceived value is redressed by one of the parties offering to make up the difference by some form of a transfer of money.
and yet, the party who experiences the pain will normally perceive the other party's *intentions* as the cause of that pain. knowing that the pain can be transformed from "can't exchange traffic" pain into "must pay money" pain tends to reinforce this perception. when this situation has existed in other industries, gov't intervention has always resulted. even when the scope is international. i've not been able to puzzle out the reason why the world's gov'ts have not stepped in with some basic interconnection requirements for IP carriers.