Montag is besieged by several forces at the outset of the novel. A couple of them are external. The most evident force is one where Montag's job is a force acting upon him. As a fireman, Montag feels pride in acting in the name of the state and burning books, whose possession the state deems illegal. In this, the force that is acting against Montag is the suposedly illegal activities of citizens who harbor books. To a certain extent, Beatty is another force acting on Montag, ensuring that he is diligent in his work and believing in its authenticity. As the novel opens, Montag finds himself subected to an internal force of wanting to do the best job he can. Montag takes pride in his work and this becomes a force to ensure that what he does is done well. Once Clarisse enters the narrative, she becomes another force that instantly acts upon Montag's purpose and what he does. Clarisse's presence also is one where an internal force is activated in Montag, wondering if what he is doing is actually right or just. Finally, Millie is a force that acts upon Montag in terms of being able to conform to the standards of society. Her desire to assimilate into society as opposed to being separate from it is another force that acts upon Montag.
The main conflicts in Ray Bradbury's science fiction novel Fahrenheit 451, and the myriad forces that act upon Bradbury's protagonist, Guy Montag, develop as the story progresses. As the student's question specifies the opening of the story, those forces are somewhat limited, but the author introduces sufficient disturbing imagery into his narrative to suggest that those forces are actually quite formidable.
Bradbury begins the novel with Montag heavily emotionally invested in his work. Firemen in Fahrenheit 451 do not respond to fires with the mission of extinguishing them. Rather, Montag and his colleagues serve society by responding to reports of hidden caches of books and, upon discovering the location of those books, proceeding to burn them and the structures in which they were hidden. Montag's mental preparedness for this profession is suggested in the novel's opening passage:
IT WAS A PLEASURE TO BURN
IT was a special pleasure to see things eaten, to see things blackened and changed. With the brass nozzle in his fists, with this great python spitting its venomous kerosene upon the world, the blood pounded in his head, and his hands were the hands of some amazing conductor playing all the symphonies of blazing and burning to bring down the tatters and charcoal ruins of history.
Montag believes in his job and takes pride in doing it well and with dedication. One could, then, suggest that a force acting upon Montag is the nature of his profession. The autocratic regime that governs this society is acting upon Montag, and his fellow firemen, by virtue of its enlistment of such men in the service of destroying independent sources of knowledge and thought. Montag acts voluntarily, but he is paid to perform this particular service, and is expected to do it conscientiously and without question.
This brings us to a component of this particular force that acts upon Montag: Captain Beatty, the commander of the fire station where Montag works. It is Beatty who will be instrumental in Montag's growing skepticism regarding the nature of his work, but only after Bradbury introduces the reader to Clarisse, a vibrant young woman who has recently moved into Montag's neighborhood and whose independent spirit proves transcendental to the fireman. Clarisse's innocence and naiveté is a force that acts upon Montag and contributes significantly to his evolution from loyal servant to committed rebel.
Technology is also a force acting upon Montag in the early phase of Fahrenheit 451. The first such intimation is the Mechanical Hound, a robotic bloodhound of sorts that is designed to sense contraband, locate it, and attack those who conceal it. That Montag may have problems with the Hound are immediately apparent in the novel's opening chapter, and it is here that the character of Captain Beatty proves especially prescient. Complaining that this inanimate object seems to dislike him, Montag engages in an exchange with Beatty:
Beatty snorted, gently. "Hell! It's a fine bit of craftsmanship, a good rifle that can fetch its own target and guarantees the bull's-eye every time."
"That's why," said Montag. "I wouldn't want to be its next victim.
"Why? You got a guilty conscience about something?"
Technology, in the form of the Hound, is a force acting on Montag, but there are others, as well. The setting of Bradbury's story, as noted, is a futuristic dystopian society. It is also, however, a society in a state of war with an outside aggressor, and the machines used to wage that war act on the fireman by contributing to the oppressive atmosphere and the tension that permeates Montag's existence. Note, in the following passage, the visceral effect the machines of war have on Montag:
As he stood there the sky over the house screamed. There was a tremendous ripping sound as if two giant hands had torn ten thousand miles of black linen down the seam. Montag was cut in half. He felt his chest chopped down and split apart. The jet-bombs going over, going over, going over, one two, one two, one two, six of them, nine of them, twelve of them, one and one and one and another and another and another, did all the screaming for him. He opened his own mouth and let their shriek come down and out between his bared teeth. The house shook.
The other forms of technology that act as forces upon Montag are more intrusive. For context, Montag's wife, Mildred—another force acting upon the protagonist—possesses blind, unquestioning fealty to the dictates of the government and acquiesces in the process by which citizens are rendered harmless. Montag is disturbed by the technology that is saving Mildred from a drug overdose:
They had this machine. They had two machines, really. One of them slid down into your stomach like a black cobra down an echoing well looking for all the old water and the old time gathered there. It drank up the green matter that flowed to the top in a slow boil. Did it drink of the darkness? Did it suck out all the poisons accumulated with the years . . . It had an Eye. The impersonal operator of the machine could, by wearing a special optical helmet, gaze into the soul of the person whom he was pumping out.
Hyperbole or an accurate description of the technology available to the government to monitor the citizenry? Montag's reaction to this seemingly beneficial medical apparatus nevertheless has a very visceral negative connotation. Technology is a major force acting upon Montag. By describing the medical machinery as "like a black cobra" that drinks "of the darkness," and that has an Eye that gazes "into the soul" of the patient, Bradbury is suggesting that technology plays a major role in the inner turmoil besetting his protagonist.