The country's protracted battle with Russia, mismanagement under previous president Viktor Yanukovych, and a painful 2014 currency devaluation have wreaked havoc on its finances, impairing its ability to pay its sovereign debt. The government is thus insisting that private investors such as Franklin Templeton accept a "last chance" deal involving a 40 percent haircut and the possibility of receiving new bonds if the economy performs better than expected. The government is threatening a moratorium on debt repayments if the creditors don't agree.
I don't believe that this should come down to 'taking sides' at all. The IMF will have looked at all the evidence that is present, heard from both parties and will have assessed and made a fair decision. The fact that the countries are Russia should have nothing to do with it; the IMF will, hopefully, also be offering advice and guidance to Ukraine about how this debt can be structured and paid in a timely and appropriate manner.
Ukraines debt is sovereign. Its debt is a result of the coup that took place that was set up by Western interests,,notable the Obama regime and others from the Western Oligarchy. Russia is a sovereign nation with a culture that goes back hundreds of years....based on Eastern Orthodox culture. It was Western financial oligarchs who set up the revolution of the Leninists in Russia and the progress of russian communism.
I think the IMF is more about getting paid. They are worried that if they declare Russia culpable for the debt that it will never be repaid. I think that they did some research and decided they had a better chance of payment if they sided with Russia. So that's what they did.