The Three Great Empires wanted to balance the books, meaning they didn't want the money anymore, considering it part of the interstellar council budget. The principal and interest didn't need to be repaid, as if the event never occurred.
As for why this happened, it's important to mention that although the interstellar council was established by the alliance of the Three Great Empires, they were not a unified political entity. In fact, the relationship between the Skrull Empire and the Kree Empire was comparable to that of England and France, with the Hundred Years' War just replaced by a Thousand Years' War. These two are mortal enemies, but they both look down on the Shi'ar Empire simultaneously.
The Kree Empire and the Skrull Empire didn't want to fight anymore and needed to recuperate; meanwhile, the Shi'ar Empire didn't want to attract the attention of the other two, so they agreed and established a "United Nations."
But even on Earth, everyone tries to manipulate the United Nations to make the situation favorable to themselves, so how could the Three Great Empires not do the same?
Therefore, when the interstellar council handles interstellar affairs, the following situation occurs: clearly an issue arises in the Kree Empire's jurisdiction, which should be resolved by Supreme Wisdom dispatching troops, but he insists on the interstellar council solving it instead.
The interstellar council's resolution requires money, and spending money requires a budget. This is Supreme Wisdom's intention: having spent money providing a budget, the money spent must be available for his use; even if not for personal use, it certainly cannot be for his enemies, hence he must use it first.
This is the thinking of every one of the Three Great Empires: having spent money, there should be a return; if a budget is just sitting idle, others will desperately use it, benefiting other Empires at their expense.
Hence everyone is desperately using it: even for small, trivial matters, they have to involve the interstellar council, regardless of the tenfold cost, to ensure profits and, more importantly, prevent others from benefiting.
As a result, no matter how much budget is granted, it is never enough. Logically, if a budget isn't sufficient, you accept the loss but the desire for advantage is insatiable. Furthermore, some issues can only be handled by the interstellar council, and they must boost the council's prestige. Not even half a quarter has passed, and the council has stalled, which isn't a good look, so more funding must be provided.
Yet to deter each other from taking undue advantage, aside from the Kree Empire, the other two Empires must also convince their internal personnel, thus metaphorically covering with a fig leaf, claiming the funds provided later are loans.
However, after repeated occurrences, there is pressure within the other two Empires: they don't want to continually supply funds to the interstellar council, even if they don't need the borrowed money returned. The Kree Empire isn't keen on lending either, at least not before a conflict with Humans arises.
They indeed have been at peace for a long time and have recovered sufficiently. While not immediately resorting to cosmic warfare, there is no need to rely on the interstellar council to maintain superficial peace. Ceasing the funding might turn the interstellar council into an ineffective structure, potentially being a better choice.
Unfortunately, they made the worst choice by choosing to antagonize the Nine Major Kingdoms. Humans went to the Shi'ar Empire causing commotion, indirectly affecting the Great Teleportation Gate Business District and leading to the decline of the Shi'ar Empire's most prosperous Star Zone and Business District; subsequently, the other two Empires attacked the Nine Major Kingdoms again, causing significant damage, bringing them all to a halt.
This damage is by no means inferior to a cosmic war amongst the three. When the era of warfare is over, isn't recuperation needed?
This recuperation requires the interstellar council, maintaining its operation is imperative, and funding cannot cease. However, the number of loans is indeed outrageous, and opposition within the other two Empires is too strong. Even to suppress these voices, some method must be devised to gloss over the problem, ensuring the interstellar council's functioning.
Thus, when Supreme Wisdom approached Shiller, it was awkward because they now need the interstellar council to maintain superficial peace, thanks to the Human race, and yet these accounts had to be settled by them.
It's not that the Three Great Empires can't falsify accounts, but the issue is their current poor relations with the Human race and using the Councilman's position to stabilize them; but if falsifying accounts under Human scrutiny, being exposed would lead to significant mockery from the Human race.
Previously, they could disregard interstellar reputations, but if Humans care, they must care too. It's similar to an arms race principle: what the opponent has, you must have too, otherwise falling behind is inevitable.
The best strategy, therefore, is to involve the Human race; once everyone is involved, no one can criticize the other. Though seemingly unfavorable for the Human race, Supreme Wisdom sought out Shiller, waiting for him to state his terms.
Unexpectedly, Shiller made no demands; Supreme Wisdom had no idea what he did, but Shiller presented a confident front, bewildering Supreme Wisdom.
Later, Supreme Wisdom became even more perplexed when the executive secretary of the finance department urgently knocked on his office door.
"Mr. Undersecretary," he hastily closed the door and said, "my minister just approved the budget for the publicity department."