It would certainly help a great deal, the Bosphorus and the southern cities were the main ports for their exports of wheat - which made up something like a third of world supply. With the straits closed the Russians were unable to export their normal commodities of grain to raise funds or import supplies in return, being able to buy in arms and materiel would certainly take the pressure off somewhat. One of the other major weaknesses for the Russians was that they were chronically short of both railway engines and rolling stock, the majority of which they imported IIRC. If they can get more of these then they can move about and manage the supplies they already had more efficiently, plus get the new supplies they're importing where they're needed at the front or to the cities.