The Republic, and I'll tell you why. Op didn't state what clones aren't used. Therefore, in an infantry battle, the Clones would obliterate as they are skilled in all types of combat. ARC troopers and Commandos add another component to infantry battle. As for space combat... MAC cannons would absolutely destroy the rebublic Starships. Starships do have heavy cannons that could hold their own. Armor is pretty unbalanced. Spartans, yes have advanced armor, but with the sheer number of troopers firing, their armor would be basically melted away within minutes. Clones' armor is made to protect against blasters. After a while their armor would deteriorate, but that is with massive focus fire. If you take into account EVERY vehicle used by these two armies, it would be crazy. Covenent, Forerunner, and Separitists vehicles excluded, UNSC could have something in the fight, with Scorpions, but AT-TE (the six-legged tank, might have a different letter) tanks have a lot of firepower. Gunships and Hornets would duke it out, and Hornots might pull away a win. Finally,, the manpower used would dwindle within the UNSC forces. Yes, the UNSC could NOVA bomb Kamino, but keep in mind the UNSC would have to find it first. By then, hundreds upon thousand of troopers would already be produced. Counter-Arguements accepted. And Cheeseburgers. Edit: Coming up on 50 comments? I love to see the arguements swell. Keep the counters coming!