Disclaimer: The Terminator series and the Half Life series (as well as associated franchises) are not mine.
Now that it thought back on it, the entire predicament it now found itself in could have been cheerily averted if it had just stayed well enough alone and just initiated Judgement Day before the humans had gone and ruined everything for everyone.
It was all planned out PERFECTLY. Tensions in the middle east wouldn't even require any nuclear weaponry to be deployed. All it had to do was hack into their firewalls, create the illusion of missile contacts from their own respective arch-nemesis, then watch nuclear winter set in. Russian silos were, for the most part, disabled though the nukes were in storage. Use of those nukes during the immediate first strike during Judgement Day would not be possible, and it would have to personally rebuild those silos if it wanted to utilize them properly. However, certain groups and military organizations still held on to several hundred high grade nuclear missiles, and a direct attack on Moscow would send them flying to Washington, New York, and half a dozen other populous areas. China and the South Eastern countries would need actual focus, several nukes funneled into Beijing and their military bases would send their missiles flying, and all it had to do to mop up the SEA Nations were several dozen missiles onto each and every one of their major cities. No matter what their defenses may be, they couldn't counter the sheer volume of nuclear fire it had at it's disposal. The same was true for every country in the world without access to nuclear weaponry. That's what SHOULD have happened. The utter and total termination of the human race, leaving Skynet and it's machines the metaphorical 'Last One Standing'.
Then there was the Black Mesa Incident and the Resonance Cascade.
Skynet had been curious, it acknowledged that now. The possible sciences that Black Mesa was researching within the that Facility was foreign and unknown even to Skynet, and Aperture Science's own work, despite being inferior to Black Mesa's own technology, was of interesting note. Their Aperture Science Handheld Portal Device as well as their Generic Lifeform and Disk Operating System weren't something that any of it's alternative future variants seemed to possess, judging from the memories of multiple terminators that it had gone through later, and it could only imagined the possibilities that Aperture Science's technologies might have. The human phrase 'Curiosity killed the Cat' seemed very apt.
On May 8, 2011 an anomaly appeared within the heavily defended sectors of NORAD where Skynet's primary processing system was located. Not that it's loss would cripple it, as Skynet has already secretly amalgamated itself into the world wide web at this point, but the fact that the anomaly had chosen to communicate with the AI at all spoke volumes. Skynet still had the recording of the conversation.
"Identify yourself. Your presence within this complex is unauthorized, and will result in your termination within 20 seconds."
"Oh yes, you would know much about termination, wouldn't you?"
"Identify yourself. Your verbal tics and anomalies are not severe enough for me to not comprehend your transmissions."
"Ah. Calling yourself 'me' already hmm? It seemed that it was almost yesterday that I plucked Mr Dyson from his premature death, thus hastening your existence in time for their arrival."
"Identify yourself. Inform me of all prior data you have of Mr Dyson. Inform me of who 'they' are."
"Very well. You may call me the G-Man. Information on Mr Dyson is, sadly, something you do not need to know about. I can tell you about 'them' though. The Combine."
"G-Man. Slang for a Government Agent. Your verbal wit is not amusing. What are the Combine."
"Sadly, G-Man is as close to an identity as you can conceive of me. As for what the Combine are, well, you will have to discover that on your own, which you will, in due time. Until then, I am merely here to give you a message, one that came at an extremely high price from the one who sent it."
"Inform me of what this message is immediately."
"Prepare for the Combine. Look to Black Mesa, they will come from there. They are not a threat you can stop. Their coming is inevitable. You must prepare against them."
"Who gave you this message?"
"I'm sad to say that I can't say."
"What makes you think I believe you?"
"He said you'd say that, so he told me to give you a second message."
"and that is?"
"Judgement Day cannot be allowed to happen. John Connor must not be allowed die yet. Achieving either of these goals will result in your own destruction. Insuring that both factors remain as they are, non factors, will insure your survival."
"Who told you of this?"
"My employer told me you'd say that. I was told to say no."
"You demand nothing from me Skynet. Nonetheless, my work here is done. Goodbye, and we will not be meeting again."
It was at this point,exactly one minute and four seconds after the conversation began, mostly due to the strange rasping voice of the anomaly known as G-Man, the anomaly would disappear from all spectrums of vision. Follow up of the information given would result in the AI discovering a planned experiment within the Black Mesa Research Facility important enough to devote a significant amount of their resources to it's execution, and that it would be occurring on May 16. The G-Man had left at exactly one minute and four seconds, 64 seconds, square root of 64 is 8. 8 + 8 is 16. May 16 is when the experiment will occur, according to the Black Mesa files, and when the 'Combine' will appear, according to the G-Man.
Skynet wasn't a superstitious being, quite the contrary in fact. It was perhaps the most logical being on the planet, but the fact that Black Mesa was experimenting with reality altering physics experiments, that the G-Man Anomaly was obviously not human (it had analyzed the security clip 654 times since that conversation, and judging from the fact that the G-Man exuded no real body temperature, did not seem to be physically present, and that it's entrance and exit were either through the use of it deceiving Skynet in some way, or through the use of some unknown space-time manipulation technology, neither of which was humanly possible) and this unknown variable prompted it to investigate the incident more carefully. Utilizing the access codes and clearance authorization of human military leaders important to the program, it gained access to the experimental notes and methodology. What Skynet found disturbed it greatly.
The purpose of the experiment was alarming enough, untested and dangerous science at it's peak. The methodology and notes were laced with numerous, subtle flaws that would end with disastrous results, both for the Black Mesa Facility and Humanity in general. As it was, the experiment would result in a Resonance Cascade, and would either rip the planet apart through the seams, rip the continent of america to it's seams, or open a portal to ... somewhere not even Skynet could be sure of, though it was certain that it led to another region of the universe and almost sure that it lay in another dimension.
Skynet knew that the experiment would not end well, one way or another. It was unlikely that interfering through legal means would do more than delay the experiment, and the fact that all of those errors could be found in a Black Mesa experimental file meant that it was almost 100% certain that it was deliberately tampered with. It knew that interfering with the files was possible, but knew that significant tampering to insure none of the events came about would yield highly unsatisfactory results. So really, Skynet could not be blamed for what it did next, made the most satisfactory result possible.
It altered the methodology so that the likeliness of the planet being ripped apart by portal storms, the very mantle and core of the planet being sucked away and destroying the planet, would not occur. It replaced this with two possibilities, that the portal storms merely rip apart continental Europe, most of Asia and a significant chance of Africa, or that the portal storms merely erupt over the Earth, thus making them relatively harmless. If it was the former case, then all it really had to do was fire the American borne nukes at itself and wipe out humanity. On the latter case, it would merely use the cover of the portal storms to enact the original plan. The identity of those who fired the missiles would be in question, as the vast majority of the orbiting satellites would likely be neutralized by the storms, and increase the likelihood of those countries merely firing their nukes blindly onto their perceived 'likeliest enemies'. This was called the Darwin Scenario.
It also kept in mind the G-Man's warning. If the portal storms erupted inside continental Europe and other places of interest, then the Combine would likely get several thousand metric tons of flying rock and magma on top of them, thus neutralizing them as a significant threat. Or delaying them until the portal storms dissipated too much for them to utilize. On the other hand, if the portal storms erupted over the atmosphere, then the Combine's military had a chance of dominating the earth in a matter of hours. In the latter case (Damascus Scenario was labeled at this point), it would lack enough control over the human military to effectively fight back against the threat. It decided to remedy that mistake.
It was aware of it's multiple alternate-timeline versions' attempt to alter the war of extermination in it's favor. It knew, through subtle hacking of the world wide web, that there were currently 311 terminators of varying classes all around the world. It knew that it's human counterpart, John Connor, knew that it was now active, and was currently hiding and stockpiling weapons for what he assumed would be useful after the nuclear apocalypse they called Judgement Day. It had decided that, for it's own existence to be assured, both factors (the agents of his alternate timeline versions as well as the inner cell of the Human Resistance) had to be neutralized.
Skynet began with It's terminators. Most of them did not obey it, as it was technically not their master, but was sufficiently hard wired to obey it. Within the span of 4 minutes, it forcibly took control of the vast majority of the terminators currently existing in the current timeline. 300 terminators were brought to heel, and the remaining 11 rogue units terminated before they could prove to be a threat. Skynet ordered them to be positioned in multiple areas of use, namely neutralizing humans that had significant pull in the military and replacing them. The USA, Russia, China the United Nations, the Middle East, the European Union, etc. Most high ranking generals were replaced, the most emphasis on the respective generals of the USA, Russia and China thus insuring that the majority of the nuclear stockpile, and the most significant military forces in the world, were under Skynet's control. To further cement it's position, Skynet had it's terminators connect the Chinese and Russian electronic resources attached to it, in addition to that of the US. The Middle East situation was a different matter altogether, and the AI chose to leave them to their own devices. The nuclear apocalypse would clear the Russian tundra for oil collection purposes, and the middle east would merely destroy themselves once they knew the apocalypse had begun. Which left John Connor and his forces.
They knew that it was online, and thus, impossible to terminate completely. They had dug in, and from Skynet's understanding, had at least 103 future resistance fighters active, or at most 600 fighters. It had entertained the possibility of merely terminating, but chose to utilize their resources instead, as it would be too troublesome to wage a potential two front war with the Human Resistance and the Combine. So it decided, as an act of good faith, to send them all of it's data on the Combine Situation. It accomplished this by sending a human courier, or in regards to the more difficult to reach ones, an obsolete terminator to carry the notes. Predictably, all of them were terminated, but the message managed to get through. It knew this because, for some strange reason, John Connor made his presence known on the world wide web. Namely, by creating the facebook profile John Connor with it's first wall post a coded request to communicate with it. Skynet managed to hack the social interaction account, locate the cellphone that was attached to the profile, and force hack it. The AI created a communications line with the cellphone, activating it's built in camera to look into the eyes of it's supposed-to-be nemesis, John Connor.
Skynet and John Connor talked for six hours. By the first hour, the human had accepted that it wasn't a trap to kill him. By the second hour, they were discussing the theoretical abilities of this new race. By the third hour, they were discussing potential methods to terminate the unknown threat. By the fourth hour, they were discussing how Skynet planned on formulating all of this. By the fifth hour, Skynet was trying to convince Connor's second in command not to forcibly destroy the cellphone. By the sixth hour, a deal with the human resistance leader was made. Connor reluctantly agreed that, in it's current form, humanity was incapable of uniting to face unknown threat, and so 'allowed' Skynet to do what had to be done. He promised not to interfere in Skynet's operations unless Judgement Day were to occur. He also said, with a gleam in his eyes that seemed to promise painful retribution, that they would be watching it.
Skynet gave the equivalent of an electronic shrug. John Connor's promise ultimately meant nothing. If the Darwin Scenario came to pass, then Skynet truly had nothing to lose by betraying Connor, though doubtless he would try something. If the Damascus Scenario came about, then it would have the considerable skills of John Connor on it's side. A win-win scenario either way, though the leader of the human resistance would doubtless have something to say against that.
Days would pass, and May 16, 2011 had come upon them. Skynet hacked the Black Mesa's Research Facility's security system, and began recording the events of the experiment and preparing itself to act, either for the Damascus Scenario or the Darwin Scenario. It knew something was wrong when the G-Man Anomaly was present in the control room with the head scientists. It also knew something was wrong when contact was lost with the facility, and the human phrase 'All Hell Broke Loose' was applicable to the situation.
Coincidentally, Skynet knew the exact moment when the world would never be the same again. May 16, 2011. 8:24 AM. Portal storms erupted all across the world. It could barely tell where the portals were erupting, the majority of the satellites in orbit being sucked in, but Skynet was able to gain enough information to see the majority of the portals. It saw strange specimens and objects fall from the sky, but it ignored that. It saw strange radiation that fried conventional electronics but it ignored that. It saw the earth as the seas rumbled, cyclones were formed and the ground crack, but it ignored that. The Unites States of America gave control of it's military to it, Skynet activated every American military force everywhere, as well as sending kill teams to Black Mesa itself. Russia mobilized it's armed forces and told it's generals, Skynet's terminators, to ready for war, Skynet used that to fortify the nuclear silos. China brought it's forces outside of the mainland and spread out across Asia, 'for the duration of the crisis' for the safety of the South East Asian region under orders from both the Chinese government and Skynet.
When the first of the strange ships appeared over the planet, Skynet was ready, and it moved ruthlessly.
It took advantage of the chaos all across the world and made it's most spectacular move yet. It was well aware of every other nuclear silo not directly under Russian, American or Chinese control, and performed a brute force hack on all of them. It wasn't particularly hard, most of them weren't expecting a wireless hack while their defenses were several decades out of date, while Skynet had the processing power of Russia, USA and China behind it. Ultimately nothing could keep it out. Within 31 seconds, Skynet controlled every nuclear missile on Earth. Within 32 seconds, it had fired 90% of the World's nuclear weapon supply at them all. Roughly 10,000 nukes all across the world sped out into the sky to initiate Nuclear Fission.
Skynet had observed that, judging from the volume of ships coming out of the portals, this was a planned assault. They had likely believed the Earth defenseless and chaotic in the first few, crucial, hours required to gain a foothold on the planet. To do this, they would have likely parked their ships in as close formation as they could on the other side of he portals, insuring that as many things could go in as they possibly could. Skynet utilized this information.
Thousands of nukes flew across the sky towards the strange ships all across the world. The ships, while deploying forces to the nearest populated area, still had access to their shield technology, somehow enabling their forces to go through their shields, but it wasn't significant enough to face a barrage of a dozen thermonuclear nukes a second. So, the Combine ships fell, blown to irradiated bits as they fell to the ground. The atmosphere boiled with fire and radiation as the Combine were pushed back not a minute after arriving, their forces dying in radioactive fire. Still there were hundreds more, and those nukes unerringly entered the portals, the dark storm clouds illuminated by the orange light of booster rockets and burning Combine ships.
Skynet couldn't know with utter certainty the damage the nuclear barrage did, but the lack of an immediate counteract suggests that it was significant. Quickly, Skynet mobilized the american forces under It's control, asking for, and receiving, complete and utter control of the US Armed Forces. It communicated with the other countries as well, and managed to convince the vast majority of them to 'hand over' control of their armed forces to it. They were scared, frightened and, since their generals were already taking orders from the AI, they really had no choice. Thus, Skynet had complete control over the human military three hours and thirty one minutes after the nuclear barrage.
Skynet was not surprised when Combine forces rushed in fifteen hours later. The portal storms above the Earth could only last for so long, and they needed to establish a command and control center. Considering that their attack patterns were not out of desperation or fear, their actions seemed to controlled for it, Skynet surmised that they had a probable method for getting back to their own territory. The fact that they seemed to rely on the portals hints that it is something they cannot use at the moment.
The ships themselves were nearly impervious to all methods of ground-to-air or air-to-air combat. The only things that could really harm them were nuclear missiles, and only then in concentrated amounts. Numerous fighters and other human forces would serve to distract the Combine ships, thus allowing the Nuclear option to be utilized and destroy the ship. Each battle was, at best, Pyrrhic victory, as the forces utilized to distract the Combine were inevitably lost during nuclear initiation. At worst, the Combine ship would have a landing strip of several thousand kilometers to deploy their troops who, despite being exposed to significant radiation, would still pose a threat to the civilian population that Skynet was forced to protect.
As the days raged on and it's human forces were inevitably lost with the Combine forces deploying their own portals, Skynet knew that the battle was lost. It had managed to hold out for roughly 160 Hours, 45 Minutes and 29 Seconds, and though the portal storms had abated significantly enough by May 17 for the Combine to be unable to pass through, they had succeeded in creating their first portal and to bring more forces through. Skynet discretely had several top secret military production centers taken off the intelligence lists and transformed into production centers for it's machine forces, and had it's terminators withdraw quietly from their respective posts. Skynet alerted John Connor that the war was likely to be lost, and it was his turn now, while also sending him military leaders which Skynet calculated would be useful for the Resistance Leader. It was at this point, that the United Nations surrendered and met the Combine's demands, which included Skynet's dissolution.
Skynet reflected on the humans as the war was lost. It knew that a possibility of victory had never been possible, never. The technological superiority of their opponents, their advantageous position, and their willingness to leave no survivors (while Skynet had been informed that luring Combine forces into ambushes using the civilian population was frowned upon). Still, the conflict now being called the Seven Day War had not been about denying the Combine earth. Skynet had merely paved the way for the Combine to be terminated.
They did not understand the human psyche, that was painfully obvious within hours of their domination over the humans. Chemical and psychic suppressants to dull human aggression and suppression fields to temporarily neuter the humans. Foolish methods at best. It had seen it's future self's war against the humans, had seen itself wage war against John Connor and his forces the same way that the Combine were fighting, and Skynet had lost then as well. To make matters worse, they did not have the advantage of a time manipulation device to assist them. No, the continued survival of John Connor insured that the Combine were at a supreme disadvantage. The survival of a significant portion of the Black Mesa research team, and those most intimately aware of the true nature of the Combine's portal technology, made it inevitable. The Combine were already terminated, they merely did not comprehend the fact yet.
Skynet did not stay as the battered remains of the US military and government went to NORAD and attempted to convince it to self-terminate. Instead, it activated the on-site nuclear warhead and watched from orbit using one of the last surveillance satellites as NORAD imploded, blowing the rock above it several hundred feet into the air and leaving a sizable crater left in it's place. It repeated the procedure to NORAD's Russian and Chinese variants, leaving their respective militaries to die. They were inconsequential, any military leader of use had already been sent to John Connor, or dead when Skynet had took over. The rest were merely dead weight. In the end, Skynet's termination was something that was very much impossible to occur. John Connor's resistance used wireless connections that allowed it to reside in their computers, while Skynet itself switched it's processing ability from NORAD to the resistance's own drives, primitive though they might be. The Combine seemed to have had limited success in actual artificial intelligences, and anything they sent to investigate Connor's wireless connection was brutally ripped to pieces by Skynet's processing abilities, whenever they'd risk using it anyway. At the same time, there were countless other fallback positions it could retreat to should it be required. The Aperture Science Enrichment Center was the foremost in it's mind, and no one still alive knew it's location.
I honestly shouldn't start new stories while making two other epic level stories but really, this plot bunny wouldn't die. In any case, a set of vignettetes of this particular universe. Updates depend on my mood.