A true career soldier, General Ashdown believed in by-the-book rules of engagement, despite the dramatic change in the state of warfare and society in general following Judgment Day. He had supported the SkyNet Initiative prior to the AI network's activation, a fact that haunted him in the years following the machine uprising. Ashdown is one of the founding members of the Resistance and was certain that tried-and-true methods of warfare would be enough to destroy SkyNet. He was also made aware early on of John Connor's "prophecized" role in the Resistance and had heard many of his radio broadcasts regarding the machines, but took no stock in such prophecies and regarded Connor as little more than a well-informed civilian. He did come to realise to some degree that Connor possessed intelligence that gave the Resistance insight into the development of SkyNet's armies, and so appointed Connor as the commander of his own special Tech-Com unit.
During Terminator: Salvation, Ashdown organised Resistance operations from the USS Wilmington, a nuclear submarine that served as the Resistance headquarters. In 2018, the Resistance had apparently discovered a code signal within the SkyNet network that apparently served as a shut-down command for the machines. Ashdown was determined to isolate this code and use it to deactivate the entire machine network in one fell swoop, organising an attack against the SkyNet Central complex in San Francisco. However, John Connor urged Ashdown to cancel the attack since Kyle Reese, the boy would become John's father when he was sent back to the past, had been captured by SkyNet forces and was being held prisoner along with dozens of other human captives. Ashdown refused to heed Connor's warnings and decided to relieve him of his command, casting him out of the Resistance. However, Connor's tightly-knit Tech-Com group all believed in Connor and refused to acknowledge Ashdown's last order.
When the arranged time of the attack against SkyNet arrived, Ashdown found that none of his subordinates in the Resistance were willing to go ahead with the attack. Apparently, belief in John Connor's prophecy was widespread and the Resistance fighters refused to commence the attack on SkyNet unless Connor himself gave the order. Unfortunately for Ashdown and the crew of the Wilmington, the signal code that would supposedly shut down the machines was in fact a SkyNet trick that allowed the machines to locate the Resistance's main command structure. An Aerial Hunter-Killer was deployed over the area of the sea where the Wilmington was operating and launched a plasma torpedo that destroyed the submarine, killing Ashdown and his entire crew.