Folks might tell you Pacific Rim is about “Monsters and Giant Robots!” 
They’re only half right. 
There’s a lot more going on in this film and I’ll try to convince you that Pacific Rim is really about: 
Growing up, releasing your ego attachment to your past and to your family. 

I can hear your groans of disbelief right now but here’s my argument. 

1. THE UMBILICAL CORD THEME
In the scene where the baby monster bursts from its monster mother, it is choked to death because it is still connected to its umbilical cord. You could say it was still tethered to its past, the previous generation, and could not proceed. That attachment killed it. 
In the model that is continually shown of the breech between our world and the other world, it appears as a ‘tether’ a connection or umbilical cord. 

2. WE NEED TO BREAK ATTACHMENT, NOT FIGHT THE SYMPTOMS 
This movie contains the ‘need to blow up the center of the death star’, ‘kill the queen alien’, ‘destroy the mother ship’ trope. It’s a common one. You’ll often see it as the ‘kill the witch and all her minions and spells will be vanquished.’ 
Here, this is (as I argue) the ‘break the attachment’/Buddhism theme. They need to cut off the umbilical cord connection to the other world, not just keep fighting the things that jump out from it. 
We see the clearest example of this when during a battle scene, the Robot’s arm crashes through an office building and gently clicks one of those desktop ‘Newton’s Cradle’ things–you know, those ‘hanging clicking balls’ things. 
This tap of the Newton’s Cradle is an image of karma…that there will always be an equal pushback and effect. Sure, the robot’s could keep getting stronger but so would the monsters. You need to get to the source. Break the attachment. 
Before you argue that the Newton’s Cradle is ‘just cute!’ consider its placement within the frame I’m presenting.

3. ATTACHMENT IN PACIFIC RIM IS ABOUT GENERATIONAL RELATIONSHIP AND MEMORY. 
The lead character (Raleigh Becket played by Charlie Hunnam) is very connected to his twin. He grieves, and grows from the loss and is able to then find new trust and connection from a new equal/peer/lover. 
The leader of the missions, Pentecost (played by Idris Elba) finally gives up the attachment to his ‘adopted’ daughter Mako (played by Rinko Kikuchi) when he hands her the red shoe he had been holding onto and allows her to go into battle. 
Just as children must let go of their family connection attachment to become fully adult, so adults need to let go of their attachments to their children to allow their children to flourish and allow themselves to continue in their own flourishing. 
To connect effectively with another robot driver, one has to ‘let go’ of thought and memory. At one point Raleigh says that the ‘drift’ is silence. A Jaeger driver may be drift compatible with another, and may have access to the equipment to meld, but they still have to ‘let go’ of their attachments. 

4. NON ATTACHMENT TO THE PAST, AND FAMILY RELATIONS ALLOWS YOU TO FLOURISH AND FIND LOVE AS AN ADULT. 
Note that upon severing the umbilical ‘breach’ to the other world, Miko and Raleigh then rise to the ocean surface in what look like coffins. They emerge from those ‘raft/buoy/coffins’ and connect in a kiss. Their new lives are in a sense resurrected as adults to freely love because of non-attachment. 
This adult love does not need to mean necessarily ‘romantic love’ though here it is pictured as such. 
Of course the ‘subliminal as underwater’ theme is likely throughout the film. 

 

I hope that this brief analysis of what Pacific Rim is really about was helpful to you! 
Surely there are more interpretations of the film and I welcome your suggestions, critiques, and differing viewpoints! 

MindFlowers