There is a curious phenomenon regarding the potential destruction of Gotham City, that is, The Dark Forest Theory is inverted. This displays itself as: when either Batman or the Joker holds a nuclear bomb button, the possibility of Gotham's destruction is minimized. However, when both of them have a nuclear bomb button and are aware that the other has one, Gotham City will unequivocally avoid destruction.
It might sound counterintuitive. Normally, a nuclear bomb button in anyone's hands is extremely dangerous, because people's hearts are unpredictable. And neither Batman nor Joker could be said to be the most mentally stable individuals, could they?
But if we delve into their individual logics, you'll find some merit to this argument.
Firstly, according to the Batman-Joker Convergence Law, all of Joker's actions are focused around Batman. So, if the Joker gets a nuclear bomb button, it's definitely to threaten Batman. The moment of maximum threat from a nuclear bomb, is when it has not yet exploded.
The Joker won't press the nuclear button because he just wants to make Batman laugh, not to kill him. All of Joker's actions are aimed towards Batman, not Gotham. If something simply annihilates Gotham without showing Joker the struggle and contradiction of Batman, Joker wouldn't use it.
Similarly, if Batman gets a nuclear button, he wouldn't press it either. If he presses it and Gotham is destroyed but the Joker survives, then some other city would just become Gotham and the destruction of Gotham would be pointless, rendering pressing the button unnecessary.
So, when both of them have nuclear buttons, they well know that neither the other nor themselves will press it, thus the probing of each other is meaningless in this case.
That said, the Joker has caused some major explosions in Gotham City. Some of which shook the city like a nuclear warhead. Yet, they never resulted from a lunatic causing uncontrollable havoc. The scale, yield, and aftermath of these explosions were all completely within Joker's control.
Ultimately, the Joker is no frothing madman. He isn't even mentally ill. Instead, he is an anti-social personality with a clear mind and not susceptible to hallucinations or reflexive problems. Therefore, in nearly all aspects, he is very rigorous and logical.
Every aspect of his plans is under his control, even the horrifying explosions. If not, he wouldn't set them off in Gotham.
In short, the Joker and Batman are similar. They are two sides of the same coin, mirror images of each other. They both possess extraordinary intellect, self-consistent logic, and nearly obsessive control, all in exactly the same measure.
But a nuclear button in their hands is completely different from one in the hands of teenagers.
Batman and Joker could even dance in front of each other, holding nuclear bomb buttons, tossing them up and down, playing a game full of terrifying threats and hellishly jocular jokes. Because they both tragically realize the truth about this City of Darkness and know that flattening Gotham is useless.
But that might not be the case for the Robins.
If a survey was conducted among people living in Europe and America, or foreigners who once lived in European and American cities, where they had two options: get involved in the fight between Batman and the Joker, or get involved in the fight amongst teenagers, and they had to choose one, the majority would definitely smash the first option button.
Anyone who has lived in Europe or America understands the terror of teenagers. Even if Batman and the Joker were to destroy the world in a few hours, the mad teenagers would destroy your fence, doghouse, and outside walls in mere minutes. They would bust fire hydrants with crowbars, drowning your plants, pop the garbage truck's tires, toppling over garbages, making the entire street stink for the next half-month...
It's hard for normal people to reason with these rebellious, mad teenagers because they have no logic, and they are extremely extreme. Based on European and American laws, regardless of what outrageous things they do, they won't receive severe punishment. Therefore, they are particularly bold when it comes to causing destruction. Infamous is an understatement.
Big foot, big lawn damage. Big capacity, big mess. Mad teenagers with baseball bats, spray cans, and lighters might at most nauseate two blocks. But if they shoulder a Tsar Bomba, carry a Katyusha in one hand, step on a missile launcher, and pocket two pounds of vodka, they would still tremble upon the Joker's arrival.
The scariest part is; Batman's actions can be predicted, his behavior is logical, but teenagers are not.
As previously analyzed, the Joker is not a completely chaotic lunatic, he's just a simple antisocial personality. He possesses superb wisdom, hence there aren't many things in this world that can surprise him. But his rationality tells him, the current situation of the Batman Family and Robin is one of them—they're not reading military strategies, they're reading recipes, and those from a Soviet arms factory.
No one can be entirely sure that a nuclear button in the hands of teenagers won't be pressed. Joker thinks that perhaps only a non-human Batman could ensure that. Therefore, he would rather go to the police station to sing amid snow in June, just to meet Batman.
When Batman arrives, Joker, while handcuffed, grips the bars of the interrogation room tightly, looking deeply into Batman's eyes. They've never before conversed in such a calm atmosphere.
The Joker seems a little uncomfortable and tries hard to swallow his saliva. He stutters a bit as he says to Batman, "Listen, Batman, there's no time for jokes now. Your little birds, they must be out of their minds, they must be. They've got a big thing, super - big."
Joker tries his best to gesture with his hands to illustrate the size of the thing, then realizes he's handcuffed and can't show just how large what he saw was. So, he can only strive to describe it with words.
"Alternating between black and white, it has a silvery tail fin. It looks like a colossal hydrogen bomb, possibly from the Soviet Union, according to the paintwork and markings. It could very well be a prototype of the Tsar Bomba developed before its actual creation, second only to the explosive yield of Big Ivan—the most terrifying part is that it might not be in its original state, they could have modified it!!!"
Joker was practically shrieking by the time he finished, acting as though he was suddenly ill. His handcuffed hands tightly clenched into fists, he pounded on the table and spoke in an exceptionally high, piercing tone.
"Batman! Your little birds not only bought a massive bomb from the Soviet Union, but they even tinkered with it. I seriously want to crack open their skulls to see what the hell they put in there! They modified it! Using drill bits and awls!!!!!"
Suddenly, Joker latched onto the bars, staring intently at Batman. He bared his teeth, revealing his gums, then said, "They plan to reinstate the mob rule in Gotham, letting those artistically inept, philosophically uninspired, completely money-minded mobsters take over our home. Batman, how can you stand idly by?!"
Batman stood calmly but sternly outside the interrogation room's bars, watching Joker's manic fit. After Joker finished this frantic rant, only then did Batman utter a word.
"Joker, I know you're trying to strain my relationship with Robin and the others. This isn't the first time you've done this but you set your sights on the other members of the Batman Family after discovering that even after you injected Spider Man with the Dark Source Elixir, he didn't turn evil."
"I must say, the lie you fabricated this time is particularly terrible," Batman said shaking his head then he went on to analyze it.
"Previously, I noticed that the chaotic mobs in Gotham had started to regroup again, and at the same time, my Robins began to keep late hours. It was as though they were all busy with something."
"Going by the usual logic, I would likely link these two events. But in reality, it's all part of your plot to alienate me from the Batman Family."
"The members of your Joker Gang haven't caused trouble in a long time. They are the ones pulling the strings behind the mob, creating the illusion of a mob resurgence. Then they plot various schemes to keep the Robins occupied, thus distancing them from me and reducing communication within the Batman Family."
"For some reason, I didn't investigate the leads to the mob unrest in time. But if I'm not mistaken, if I were to follow these leads, I would certainly see traces of the Robins. This is your devious setup with the aim of making me believe that the members of the Batman Family have betrayed me and become my enemies."
"But Joker, you acted too hastily," Batman squinted his eyes slightly and said, "You noticed that I had a new Robin, so you rushed to implement this plan against him."
"First, you created the Dark Source Elixir and injected it into Spider Man, hoping he'd go mad and turn against me, making me feel isolated."
"But seeing that the elixir had no effect, you then targeted Spider Man's psychological state, attempting to show him the dark side of Gotham to make him see me as his enemy and thereby driving a wedge between us."
"Originally, I wasn't able to connect the sudden rise of the mob and the fact that the Robins hadn't been coming home. However, the plot you laid out against Spider Man reminded me that Spider Man isn't your only target."
"You used Spider Man as a decoy to draw my attention, so that my worry for Spider Man falling into darkness would distract me. But in fact, your real target is the other members of the Batman Family. You had already laid traps for the other Robins even before Spider Man came into my line of sight."
Batman took a step forward, looking into Joker's eyes and said: "But you can't deceive me, Joker."
"You appearing at the police station is simply to make me think that Robin's crazy actions have forced even a dangerous criminal like you to turn yourself in and seek help. That the members of the Batman Family must have turned extremely evil."
"Your panicked plea for help is nothing but a show to illustrate that you're on my side now, and Robin is our common enemy."
"But you're mistaken, Joker," Batman lightly waved his cape and turned to leave. In the deserted and dark corridor of the police station, only his typically grave and stern voice lingered.
"Even if you've started scheming a long time ago, setting traps, and manipulating events, I will never view my children as my enemies. The darkness in this city was forged by the likes of you. Batman can't be fooled, and he won't turn against Robin."
"Give up your plot to fracture the Batman Family, Joker. You won't succeed."
Joker watch stunned, as Batman walked away.