> decades-long Iran/Iraq war was a proxy war fought between the US and the Soviet Union with both sides having the goal of creating a dominant footprint in the middle east
No. Last Soviet attempt to gain a foothold in Middle East was a failed relationship with Egypt. Hint: War of Attrition followed by Yom Kippur War.
There was no major influx of military advisers or green men during Iran-Iraq war.
> The Soviet Union was too big and plagued by infrastructure problems, but Russia itself is well placed geopolitically and has historically been a seat of wealth, culture, and regional ambitions.
I have a bad news for you - Russia is about the same size as USSR and it's still plagued with infrastructure problems. And as for the culture - everybody can see the decline in post-Soviet cultural scene, especially in Russia.