one of Batman Most defining character traits is how hard it is for him to trust anyone. Batman is a deeply paranoid person, which makes it difficult for him to work in teams. He plotted against his allies countless times and even created contingency plans to defeat them, and DC once revealed the source of this paranoia.
The root of Batman's inability to trust his teams is revealed in Batman Confidential #54 by Marc Guggenheim and Jerry Bingham. In this story, Bruce Wayne is still traveling the world trying to learn the skills he will need to become the Dark Knight. Batman ends up in China, where he meets the warlord Huiren, who has destroyed the countryside. Unable to defeat Huairen alone, Bruce teams up with the Zhuguan.
The Zhuguan are A group of heroes whose name roughly translates to "The league." Batman first tries to team up with the "First League," but unfortunately, it doesn't end well for him. This terrible first experience with teams is the big reason why Batman finds it so hard to trust the Justice League later on.
Batman's first league was a traumatic experience
Batman: Confidential #54 by Marc Guggenheim, Jerry Bingham, David Baron and Ken Lopez
The Zhuguan is not the best team for Batman. They were men fighting a war, and they intended to win the war with lethal force. One of the ways they fought this war was through the use of a special drug that gave them power, which they offered to Batman as well. Not knowing any better, Bruce accepted it and briefly gained superpowers. During a final confrontation with Huairen, the Zhuguan manipulates Batman into nearly using lethal forcePromised that they will use their powers to revive the Hoirs afterwards. When they almost break their promise, Batman realizes how foolish it is to trust people with powers.
Batman prefers to be alone because there are no uncontrolled variables.
Batman often creates control, Given that his parents died in a moment of chaos. It is not unusual for Bruce to be remarkably uncomfortable in situations where he has no control, and this is especially true when he is faced with god-like beings such as Superman. Batman prefers to be alone because there are no uncontrolled variables. Even Robin is someone he personally trained and knows as well as himself. But after the Zhuguan try to get Batman addicted to opium, which is what their superpower-granting drug is based on, and try to make him break his one rule, it's understandable that he'd want to avoid teams.
Batman distrusted the Justice League for years after this first team experience
And some stories prove that he was right
It is immensely difficult for Batman to trust people he cannot control. While there is no denying that Batman wanted to trust the Justice League, just as he wanted to trust the Zhuguan, he had been betrayed before. The Zhuguan tried to get Batman addicted to opium and trick him into breaking his one rule, and the Justice League once wiped Batman's memory to cover up their crime in Identity crisis By Brad Meltzer and Rags Morales. While Batman Tried to believe in the good of people, some key events have made it understandably difficult for him to always trust with teammates.
Batman Confidential #54 Available now from DC Comics!