Our organization of visiting races has been and will continue to defend our race from other outside races.
They defend our interests in our race and world, and keep each visiting race working together on the same page.
No other race can visit our world without permission and escort by this organization.
(Every world has an organization of visiting races which is made of its neighbors in the space they share.)
There are no rogue races traveling around committing drive-by shootings of neighboring worlds.
No hoodlum or gangster aliens stealing shuttles to go looking for some trouble.
No professional takeover of worlds or natural resources.
No slavery of people of animals.
There is no such advanced organized crime or attack possible to have grown into existence within the organization of all of known evolved space.
These can only exist in a bubble, as there is around our own race on Earth, and it can't continue to evolve to advancement.
The "bad" aliens you refer to would be the particular humans from our race doing out in space what they do here at home.
They run our world now, and our visiting races already protect themselves and each other from them, and from the emanating residue of their bombs, and from their missiles launched at them, and from their trash and pollution.
Our race will not be allowed to travel, or even invited to participate with our local group of worlds, until our leaders are permanently trustworthy and peaceful.
Advanced worlds do not war and such.
If they did, nobody would survive.
Nobody would be here.