I am attaching an excellent writeup of the current machinations of the United States to invalidate sovereign debt payments that Ukraine owes to Russia. As always, the IMF is being used as an economic weapon and its rules are being altered to suit U.S. imperial/corporate interests. This is something of a long read, and it does assume some familiarity with recent events, but it does an excellent job of explaining the rule changes themselves, as well as their ramifications in the wider world.
For me it has been very interesting to watch how the U.S. centered world reacts to the creation of the Asian Infrastructure Investment Bank and the BRICSbank. I have no idea if these new global financial institutions will ultimately prove to operate more fairly than the World Bank and the IMF (I hope so though), but I do think that having more such alternatives will incentivize better treatment of nations receiving loans. Competition might force some change on the world stage.