Steer up what war? the first war? The 1st hokage gave out tailed beats to all the nations as a sign of peace. They got greedy! The uchiha clan got nothing to do with that. They all couldn't just leave the village. If they left, other nations would see the hidden village weaken and attack.Because it was their leader that steer up the war. But instead of live in peace, they want to destroy the village... They werent live in a cage, it was a fking free land, enough of food...bla bla bla, maybe not as good as the inside village but definitly better than the sand village. What will they gain if they kill the hokage and many innocent ?
They don't plan on killing innocent. Only take out the leaders. But really. They didn't even have a plan in motion yet. They was simply collection information through itachi.
Bottom line, The leaders didn't want to treat them as equal because they were afraid that Uchiha will let the power go to their head and that they will take them out.
If they had treated them equally, The hidden leaf would have the Uchiha's strength in all of the 3 great wars and stomp all of the other nations.