There's an old short story by Alan Dean Foster touching on that idea. Earth is isolated behind a force field because it's considered so dangerous until an alien

There's an old short story by Alan Dean Foster touching on that idea. Earth is isolated behind a force field because it's considered so dangerous until an alien empire under pressure from an undefeatable foe has no option but to ask for help. No spoilers but it's a good story... With Friends Like These https://archive.org/details/withfriendsliket00fost https://archive.org/details/withfriendsliket00fost Another great story from that collection inspired the board game "Car Wars".