Your wrong on two accounts:
For one thing, it wasn't Obito that waged war against the entire Shinobi world. It was Madara. The whole world was under the impression that Madara was alive and well. If Obito didn't have the mask on and wasn't posing as Madara, the Kage wouldn't have taken him seriously and most likely wouldn't have created an alliance.
Two, Obito definitely isn't the true main antagonist of the series. That position goes to either Orochimaru or Madara. Orochimaru im not sure about yet, as his intentions are his a mystery. But Madara for sure has a much better establishment as a villain than Obito. For one thing, all of the events that have occurred so far were all under the impression that Obito was Madara. Thats fact. Madara has the strength bonus as well currently, as the only person on the field that has a chance against Madara is Hashirama. So Madara has the god complex going for him. Madara was essentially the originator of all this, as it was Madara who brainwashed Obito, in a very similar relationship as the Emperor did to Darth Vader/Anakin Skywalker. Obito is just the puppet, the successor, the sorcerers's apprentice.
