Why on earth would someone be so ready to bankrupt a country, like Ukraine? There is absolutely nothing to gain in a war like this, a war that Ukraine cannot win against a bigger country, a nuclear power. The Americans would not dare to fight Russia openly, and definitely not any of the European country. A caveat, there would be a few lunatics that think it is ok to go to war with Russia.
Because of the fear of an uncontrolled and menacing nuclear war between Russia and the USA, the Americans took measures to control and limit the scale of this war, to be localised only inside Ukraine boundaries, never allowed to breach the borders of Russia. It would just be like Syria, both sides fighting with one hand tied behind their backs. Under this self imposed restraint, the war in Ukraine would always be in Ukraine till kingdom comes. The Americans are happy with that. The Russians can live with that.
In the meantime, the Ukrainians would just keep dying or run away from Ukraine. And Zelensky will keep on shouting and fighting this war with his mouth. More aids, more aids and more aids. Why? The aids are not for free. Whatever that were sent to Ukraine must be paid back someday. would Zelensky care?
He lives for the moment, enriching himself the best he could. He is not going to pay back the hundreds of billions of debt incurred in the war. He would be gone when the situation turns. The debt would be shouldered by the Ukrainians if there is still a state called Ukraine. If Ukraine is broken up, all the debt would be vaporised in thin air. The Americans and Europeans hoping for their payback can only hope till eternity as there would be no one, no country to pay them. Even if Ukraine still exists, the new govt would be in no position to pay back and at best could drag on till eternity.
The immediate beneficiary, the Military Industrial Complex would be happy to charge the US govt for the weapons they provided and sent to Ukraine. Ultimately the American public presumably would be responsible. But the debt would be just on paper, to be added to the trillions of debt owed by the US govt.
No one would be responsible for this debt as the creator and conspirators to this debt woud be long gone, disappeared. Zelensky, if he survived the persecution, would retire in some corner of the earth, enjoying his loot from Ukraine.