Could Gandalf have won the war alone?

[CSteefel]

Originally Posted by Raynor

This is the One Ring that he lost many ages ago, to the great weakening of his power. He greatly desires it – but he must not get it.

I was referring to the increase in his power relative to his primitive state as a Maiar. Now the question is, what is his power when he does not possess the Ring, but when it still exists (basically, his situation in the Third Age). Admittedly, he must have been more nearly equal with a Saruman or a Gandalf, but we see him giving the Witch King more power just before the Siege of Minas Tirith. Stated another way, does the loss of the Ring bring him back to Square One, his power before the forging of the Rings, or is his power still beyond that since the Ring still exists and answers to his will???