Iraq could use Russian financing to rebuild the country. Iraq would need massive help, like the Marshall Plan at the end of WWII, to rebuild their infrastructure and economy. This would help bring Iraq out of the darkness they now encounter and give Russia claiming rights to some of Iraq oil.

If it did then the USA would be a Communist State!!

If I understood well "Russia even wrote off a substantial part of the Iraqi debt hoping it would bring it some concessions and preferences". Which goes up to 12 billion dollars! So why would Russia pour even more money in the form of the investment, before getting some lucrative contracts ?! And USA position on all this ? Unfortunately we don't have that answer either. All in all, it's not going to be easy to transform wishful thinking in reality.

Balanced engagement by all parties in Iraq is healthy and necessary. The intent is not for Iraq to become a satellite of this, or that, but instead to become a sovereign. Nation. Therefore, the Russians are not only welcome but needed. The quickest way to end the war is to jump start an economy and Russian investment is as welcome as any.