(covers information from an alternate timeline)
This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
The Temporal War began when a rogue time-traveling faction, the Na'kuhl, returned to the 29th century after making several changes to Earth's history. With this egregious violation of the Temporal Accord, all the time-traveling factions began attempting to wipe out the others from existence. As a result, an already-existing Cold War escalated into a full-scale conflict.
After being defeated in the Temporal War by the last of the temporal agents, the Na'kuhl Vosk escaped through stealth time travel to the 1944 of an alternate timeline where he and his faction used 20th century technology to build a temporal conduit to return to their own time. Once in their own time, the Na'kuhl defeated the temporal agents and the Temporal Cold War turned into a full Temporal War with each faction causing dozens of changes throughout the timeline in an attempt to wipe each other out.
In a desperate attempt to avert the Temporal War, the temporal agent known as Daniels transports Enterprise NX-01 and Captain Jonathan Archer from end of the Xindi incident to 1944 of a Na'kuhl-altered World War II. Daniels hoped that by stopping Vosk from returning to his own time period, the Temporal War would be averted and the timeline restored to normal. The Cabal's mysterious benefactor also dispatched Silik to stop Vosk and gain the plans for the temporal conduit so he could use the technology for himself and his own faction.
After arriving in 1944, Enterprise and her crew learned of the altered timeline and Vosk's presence. Before dying, Daniels informed them of the events leading up to the Temporal War and the need to kill Vosk to prevent it. As Vosk's compound was equipped with shields, Archer decides to enlist the aid of Silik to enter the compound lower the shields so that Enterprise can bomb it and destroy the temporal conduit. With the help of Alicia Travers, Archer is able to enlist the aid of the American Resistance to attack the compound as a distraction. As the Enterprise was damaged by Vosk's plasma cannon, it will need to get close enough to bomb the compound directly using visual scanners. (ENT: "Storm Front", "Storm Front, Part II")
Battle over New York
Under the command of Carmine, a group of American Resistance Fighters assault the entrance to Vosk's compound, killing several Nazi soldiers. As the resistance fighters start to get outgunned, Alicia arrives with more fighters. The Na'kuhl detect the development but Vosk sees it as a fortuitous development, telling Kraul that the Nazis will be too distracted dealing with the resistance fighters to interrupt their preparations to return to the 29th century.
As the resistance fighters distract the Nazis, Archer and Silik sneak to a side door into the compound which is locked from the inside. Silik is able to use his Suliban enhancements to make his way through a vent next to the door and let Archer into the compound. Archer reports on the developments to T'Pol who informs him that the Enterprise will have to enter the atmosphere in order to target the facility. Archer orders her to do so once the compound's shields are down. Despite having to briefly hide from enemy forces, Archer is able to use a console and the information from Silik's data disk to lower the compound's shields. Archer and Silik are then engaged by Nazis and take them out, but not before Silik is shot and mortally wounded. Though Archer tries to signal Enterprise for beam out, he is unable to reach them due to ionization in the atmosphere and Silik dies moments later. Attempting to leave the facility, Archer encounters Trip who had been previously trapped there by Silik. After seeing Silik's body, Trip realizes Archer is who he says he is and they flee the compound together.
After Archer lowers the shields around the compound, T'Pol orders the Enterprise into Earth's atmosphere. Detecting the development, Vosk orders the plasma cannon deployed, but his men aren't able to spare the power while attempting to use the temporal conduit. Instead, Vosk orders his squadron deployed. The Nazi Generalmajor attempts to take the squadron from Vosk, but Vosk kills him and his men and orders his squadron deployed.
On the Enterprise Reed reports that targeting scanners can't get a lock and switches to visual scanners. T'Pol orders the Enterprise slowed to 200kph as Hoshi Sato detects the launch of Vosk's squadron.
Outisde the compound, Trip and Archer emerge and Carmine has Nicky Giorgo cover their retreat. Archer warns Carmine of the coming bombing and has the resistance fighters flee. Archer promises Alicia to restore her life to normal and he and Trip beam back to the Enterprise.
On the Enterprise, the crew initially believes the approaching squadron to be harmless but discover them to be equipped with plasma cannons. Archer enters and takes command ordering photonic torpedos prepared as the Enterprise uses her phase cannons to fight off the squadron.
In the compound, the Na'khul are successfully able to open the temporal conduit into the future and Vosk prepares to return to his own time. Moments before Vosk can return to the 29th century, Reed reports he has the compound targeted and Archer orders him to fire. Closing to point-blank range, the Enterprise fires three photonic torpedoes at the compound, destroying it as Vosk enters the conduit, destroying the conduit before it can be used and killing Vosk. (ENT: "Storm Front, Part II")
Following the death of Vosk, the restored Daniels informs Archer that the Enterprise was successful: Vosk was killed before he could return to the 29th century and spark the Temporal Cold War into a full Temporal War. With Vosk's death, all of the damage to history is reversed and the correct timeline is restored. Daniels tells Archer that the battle ended the Temporal Cold War for good and returns Archer and the Enterprise to their own time. (ENT: "Storm Front, Part II")