China's debt is no different from other countries. Japan is above 200% GPD for example, Italy, Spain, Greece, France... all have debt for decades.
Japan, italy, spain, greece and france. Are all too far into debt to donate funds to ukraine.
Eventually the united states will be as well.
What happens then? When russia still has low debt and can afford to mobilize.
The united states spent more than $12 trillion dollars on military operations in the middle east. Eventually that money can run out and nations cannot defend themselves (or ukraine) without bankrupting their budget.