If we take the Biblical account seriously, this would only mean that Jesus had given in to Satan's Temptation to become a Earthly king. In a Christian framework, this would be like a Second Fall, a non redeemable one. "Disaster" does not even begin to describe the matter. The Light went into the Darkness and turned itself off.
If we take the Biblical account seriously, this clearly indicates that we're in a universe where God had a different plan for Jesus than the one the Bible says he had in this universe. One where Jesus is more like a perfected David or Saul than the Jesus from our universe. Presuming this, well, the Romans are kind of fucked, since after all they're fighting the all-powerful, all-knowing God of the world; they obviously can't win this.
I suppose the outcome of this Biblical (or near-Biblical) Jesus revolting against Rome depends on just what God's actual plan is--just to restore the Kingdom of Israel, perfected (i.e., turn it into something like the various visions of the New Jerusalem found in the Bible)? Well, that probably has relatively little impact in the short term, actually--the angels or whomever push the new Israel to the borders that God wants it to have, then just sit there and defend it. Those borders encompass a substantial swathe of the eastern Mediterranean coast, but ultimately they don't really threaten the Romans so much. The Romans probably get a bloody nose a few times, then realize that they're not going to retake Israel and switch to a more diplomatic mode. In the longer term, having an apparently divine power on Earth will very likely cause a lot of people to convert to Judaism--I mean, you can go to Jerusalem and see the power and might of the Hebrew God, it's going to be a very convincing and powerful argument. Doubly so if Jesus just sticks around being King of Israel forever. Judaism itself will obviously look different, with Jesus clearly being accepted as the Messiah and an extremely different series of historical developments from this point onwards--instead of being a minority religion decimated and driven out of its own homeland by a series of failed uprisings, it will have literally divine sanction for its truth and power.
On the other hand, suppose God's plan was instead to conquer the world. He got tired of all of this nudging and decided to do some right spanking. Well, that's going to end badly for everyone except the Jews, probably (and even then only most of the Jews). Again, they're fighting the all-powerful, all-knowing God; there's no way that they can win against whatever plagues and famines and armies of angels and softened or hardened hearts he can bring. I wouldn't expect it to take more than decades for the Kingdom of God to encompass the entire world. Like in the other scenario, this will certainly lead to the Jesus branch of Judaism becoming dominant, Jesus being universally accepted as the Jewish Messiah, and widespread conversion--more widespread than in the other case, of course, since
deus vult, so to speak.
There was a short story buried in another, similar thread somewhere on this forum some time back that had Jesus carving out a kingdom or empire in the east, sustained by armies of angels and the like, which probably pretty well spells out the ASB/Biblical version of what this would look like. It even had Jesus coming back angry from the Crucifixion.