Tiberian Dawn is the name given to the first game in the series, released in 1995 and initially known simply as Command & Conquer.
Brigadier General Mark Jamison Sheppard
Brigadier General Mark Jamison Sheppard was the first supreme commander of the (then) newly instituted and multinational Global Defense Initiative task force. During the period known as the First Tiberium War, GDI forces around the world waged the initial war against the Brotherhood of Nod under his leadership. Sheppard was a United States general before being tapped to run the newly formed GDI. He is one of two people who frequently brief the player about the next mission. Sheppard was often absent from his command post for various reasons, and toward the end of the GDI campaign he showed great remorse when Kane eluded GDI in mission 13.
Gen. Sheppard also had a son serving in the GDI special forces, Logan Sheppard, who had to compensate all the time for the fact his father was a high-ranking GDI commander.
Interestingly, General Sheppard’s rank and stars apparently do not match up by United States military standards: Sheppard has three stars per shoulder pad, which by US standards would make him a Lieutenant General. These errors may be explained if Sheppard is actually wearing a GDI uniform that may just resemble a US uniform. In that case, the ranking structure and awards (such as the aiguillette) could be unique to GDI and not necessarily follow the US pattern - as evidenced by the inclusion of Commander and Lieutenant Commander ranks within the traditional GDI army. It is also possible that Sheppard held the rank of Brigadier General in the US Army, and his new position came with a provisional promotion to Lieutenant General.
Dr. Ignatio Mobius
Also known as Moebius or R.H. Mobius, Dr. Mobius was the world's foremost expert and leading scientist on Tiberium prior to and during the First Tiberium War, for instance, appearing on a science conference in Hong Kong to verify claims about Tiberium toxicity.
However, later into the war, his attitude would change drastically, as he learns of the effect Tiberium has on plant life, livestock and, most importantly, humans. To this end he would set up a hospital site for civilians afflicted with Tiberium poisoning in Slovakia, near Bratislava.
Towards the end of the war, Dr. Mobius was captured in a Guatemalan GDI research facility, along with his daughter, Dr. Sydney Mobius and his assistant Dr. Elena Petrova. This was done by the Brotherhood of Nod special forces unit known as the Black Hand. The operation was personally overseen by general Gideon Raveshaw, founder of the unit, who was also tasked with safeguarding project ReGenesis. Dr Mobius was forced to work on the eugenics program along with the other captured scientists. Eventually, he would be rescued by Captain Parker, a GDI Commando, from the depths of a Nod Tech Center.
Mobius is officially credited for having first discovered Tiberium along the Tiber River, from which the substance got its name. However, if the player has sided with the Brotherhood of Nod the Brotherhood's leader Kane dismisses this claim, saying he discovered Tiberium himself and that he named it after the Roman emperor Tiberius. Kane dismisses Mobius as a quack and a fraud, in his words, "an obvious lunatic."
Dr. Mobius along with his science staff was killed in an Ion Storm following the First Tiberium War. However, according to the novelization of Tiberium Wars, he is killed when the Philadelphia station is destroyed.
Colonel J.C Carter
One of GDI's field commanders during the First Tiberium War, he always kept closely in touch with the player, especially after contact with General Sheppard was lost and GDI's field commanders were forced to take charge directly. His final fate is unknown, though it is believed he was killed onboard one of the GDI Gunboats destroyed by one of Nod's earliest Obelisk of Light prototypes.
Carter is portrayed by Bill Collins.
Colonel M.O Morelli
An excellent fighter pilot and commander of Global Defense Initiative's air force. She is responsible for maintaining and commanding GDI's airforce, as well as briefing field commanders on occasions. The player received a briefing from her in the fourth GDI mission, in Białystok.
She is portrayed by Wendy Bagger.
Captain Nick "Havoc" Parker
Captain Nick "Havoc" Parker is a GDI commando with a characteristically bad attitude. He is the primary character in Renegade. Before joining GDI, Parker was a US Marine who excelled in the use of high explosives. He was recruited by the GDI and cycled through special forces training before being assigned to GDI's elite "Dead-6" commando unit. Eventually, Havoc quit the unit and began operating solo (upon hearing that Locke wants him to work with the Dead-6 again, he coldly replies with "I work alone."), using his special forces training to fight Nod his own way.
According to Mike Verdu's Tiberium Wars blog, "Havoc" is still alive in 2039, a retired war veteran holding the rank of colonel. He is a conservative pundit who was opposed to the retirement of the Mammoth Mk. II and was a strong proponent of the "Kane lives" theory. This is confirmed in the game in one of the many intelligence documents the player can collect.
A statue of Havoc can be seen in the Pentagon mission in GDI's campaign. It is located toward the left portion of the map. 
Havoc is voiced by Wally Wingert.
Brigadier General Adam Locke
Brigadier General Adam Locke is Havoc's commanding officer. He is chief of GDI special warfare operations, and has commanded Havoc for two years. Locke operates a group of GDI’s amphibious assault ships, and constantly updates Havoc’s EVA unit with mission objectives and critical commentary. Before he joined GDI, Locke was a member of the British Army and is considered somewhat of a rogue himself by his peers; he was chosen to deal with Havoc because he can tolerate a bit of insubordination by his men. As with General Sheppard, Locke wears three stars on each shoulder, which implies his rank is equivalent to that of an American Lieutenant General.
Adam Locke is voiced by David Lodge.
Lieutenant Adriana Maus
Lieutenant Adriana Maus is a communications officer aboard General Locke’s flagship. She is frequently seen in the background of video briefings held aboard Locke's ship. Maus has some authority over GDI forces deployed in combat zones, as is evidenced in the second mission of Renegade, when a group of rifle soldiers were ordered by Maus to hold their current positions instead of assaulting a Hand of Nod.
The Dead Six are a group of Six commandos that GDI frequently deployed for special operations and other sensitive missions. At the time of their introduction in Renegade the team had lost two members —Havoc and Sakura— yet despite this retained the name "Dead-6". The name Dead-6 refers to the legal status of the team’s members: each person in the group has been officially KIA, and hence no longer exists. This makes it easier for the team to remain covert and helps GDI by giving them a greater degree of plausible deniability when discussing the team's operations.
Daryl "Deadeye" MacInnis
Deadeye’s real name was Dariel MacInnis. Originally from Scotland, Deadeye is a tactical field sniper with incredible accuracy; he has a nearly flawless ratio of shots fired and targets hit. He was formerly a member of the British Special Air Service before joining GDI.
Strangely, Deadeye seems to speak with an Irish accent in-game, despite his Scottish heritage.
Nigel "Gunner" Grant
A GDI special forces rocket soldier with a massive frame, Gunner is responsible for operating the heavy artillery, as his primary weapon is a rocket launcher. His real name was Nigel Grant, born and raised in London's worst parts. He made his mark in the British Special Boat Service (an equivalent to the US Navy SEALs) before joining GDI. Gunner has a faster rate of fire than both Rocket Officers and Rocket Soldiers, which allows him to eliminate potential Nod threats faster. Among the members of the Dead-6 Gunner has, by a wide margin, the largest and longest speaking parts.
He is voiced by Andre Sogliuzzo.
Shai "Hotwire" Aviv
Prior to joining GDI, Shai Aviv was a member of the Israeli Mossad, where she served with distinction. When she joined the Dead-6, she took on the roles of tactical engineer, proving to be an invaluable asset on the battlefield, when vehicle repair, structure capturing and demolitions were needed.
She carries twice as much C4 than a regular GDI engineer and repairs vehicles and structures twice as fast. She is also the only GDI infantryman able to deploy landmines.
Erich "Patch" Wulfe
Patch is a specialist grenadier for the Dead-6, using a Grenade Launcher as his weapon of choice. He was the only member of the GDI commando team to successfully complete his mission during the village battle in Renegade, reaching the established rendez-vous point in the town's cathedral on his own (Hotwire, Gunner & Deadeye are all unable to reach the cathedral and are pinned down in various places until Nick Havoc Parker is able to rescue them).
Patch hails from Germany, Berlin to be exact, and has served with the GSG 9 counter-terrorist unit prior to joining GDI.
Sydney Mobius is Dr. Ignatio Mobius' daughter. Unlike her father, Sydney is driven to use Tiberium as a weapon on the battlefield. She worked with GDI to develop the "Mobius Suit", the precursor of the Zone Trooper armor. Like her father, Sydney is one of the worlds foremost experts on tiberium, and frequently reports her findings to the GDI. She was captured with her father and forced to conduct Tiberium research for Nod before being rescued by GDI special forces. During a recon mission she was recaptured by Nod special forces and exposed to Tiberium before being rescued by GDI commando Nick Parker. She subsequently sabotaged Nod's nuclear missile, causing it to explode within the Temple of Nod.
Sydney is voiced by Leigh Allyn Baker in Renegade.
The son of Brigadier General Mark Jamison Sheppard and bore the rank of Lieutenant. Due to the fact he was the son of a general, he had to work hard to prove that he didn't get his position in the GDI due to nepotism. He is Havoc's instructor during the refresher course Capt. Parker receives, and doesn't appear again in the main campaign.
In the original concept for Renegade, Logan was used as the main protagonist and had the codename Havok.
Command & Conquer: Tiberian Sun is set thirty years after the events of Tiberian Dawn, and introduces a whole new cast of GDI characters.
General James Solomon
The commanding general of the GDI in Command & Conquer: Tiberian Sun, James Solomon was a decorated war veteran from the First Tiberium War. It was his elite task force which led the final assault against the "Temple of Nod" in Sarajevo and which had caused the Brotherhood of Nod's first downfall, insinuating that he was in fact the player-controlled commander of the first game.
Due to his veteran and distinguished status as a senior GDI officer, James Solomon was unanimously nominated to become the second leader of the Global Defense Initiative's forces in succession to Mark Jamison Sheppard. He exercised his command authority from GDI's orbital main base of operations, the space station "Philadelphia", throughout the Second Tiberium War. Solomon was often portrayed as a responsible and strong leader, yet he apparently held mutants in low regard, often referring to them as "shiners" and saying that they "can wait."
It is unknown what happened to Solomon during the period between the second and Third Tiberium War. It is possible that he either retired, or was killed when the "Philadelphia" was destroyed at the advent of the Third Tiberium War.
The role of General James Solomon was played by James Earl Jones.
Commander Michael McNeil
GDI commander Michael "Mack" McNeil was placed in charge of GDI forces during the Second Tiberium War. He was a hard headed commander with a reputation for doing everything in his power to win, though he occasionally takes heat for his battlefield decisions. GDI medical report No. PSY89902 describes him as fiercely loyal and a highly competitive man, focusing tightly on what he had to do. McNeil's base of operations was the command ship Kodiak.
At the beginning of the GDI campaign, he can be seen practicing in the southwestern GDI training facility. Chandra interrupts his training, informing him that General Solomon needs him. Informed of the reappearance of Kane, he is skeptical at first, but nevertheless rushes to reinforce Phoenix, a GDI military base that came under attack from Nod troops. While successful at it, he didn't manage to save commander Tao, who was executed by Nod enforcer Vega, archived on a video recording recovered in the base. Upon completing the next mission, a GDI scout force in Area 7 found a large crashed aircraft, easily as large as a GDI carrier. As McNeil learned of it, he took steps necessary to secure and ensure the integrity of the crashed Scrin ship.
When infiltrating it with his second-in-command, Chandra, they were ambushed by Umagon, one of the The Forgotten. After a brief fight, Umagon struck a deal with GDI, exchanging support of the Forgotten and General Vega's location for saving Tratos, their leader imprisoned within a medical facility belonging to the Brotherhood. Succeeding in this assignment (routing CABAL's elite Cyborg guard with the help of the mutant, Ghoststalker, and the Mutant Hijacker), GDI learned of general Vega's base of operations in South America. His pyramid was infiltrated after the battle by Commander McNeil and Chandra, but they failed to apprehend the general, who committed suicide (with his own Eye Candy drug) after Kane launched an ICBM to obliterate his island, a threat that McNeil and Chandra narrowly escaped.
Just a few moments later, McNeil was informed that the Norwegian GDI base, Hammerfest, was taken by Nod troopers. His brother, Jake, was stationed there as a high-ranking officer, and even though GDI swiftly recaptured the base, he was executed in a "slow and painful" way, a fact about which Kane gloated to McNeil in an on-screen transmission. It seemed that before GDI could move on to Hammerfest, the Black Hand managed to steal important sonic crystals.
As GDI tried to track down Kane, a massive Tiberium missile attack was unleashed on Europe by the Brotherhood, which started a chain reaction reformatting matter at a molecular level. McNeil was ordered to search and destroy the missile factory.
This mission was divided in several parts, for the Black Hand was overseeing this project with extreme precautions. Umagon requested the liberation of approximatively fifty Shiners of the Forgotten used to as slaves for Cybernetic experiments. Although General Solomon restricted that operation saying "the Shiners can wait", McNeil agreed to send Umagon, Ghoststalker, the Mutant Hijacker and their brethren to save the mutants on the condition that they support McNeil's troops during the assault of the Nod's chemical factory.
It was also revealed at that moment that Tratos once was a slave to Kane and he was used to translate the Tacitus for the Nod leader. The Forgotten leader regretted to have betrayed the world but Umagon reassured him by saying that he had no choice since he was enslaved.
Following the destruction of the chemical factory, McNeil received another assignment; to find the source of Nod's Banshee prototype fighters who successfully damaged the Kodiak carrier. Umagon helped to pinpoint the exact location of the base, but she was captured by Nod troopers and delivered to Kane. Shortly after accomplishing the mission, McNeil's command ship was grounded by an ion storm, an occasion which Kane used to attack McNeil. The assault was foiled, however, and McNeil survived.
Learning from a transmission from the Forgotten's commando, Ghostalker, McNeil learned that Umagon was being kept within Kane's pyramid near Cairo, which was constructed on an island not far away from the Cairo Temple of Nod. Disobeying Solomon's orders, McNeil rushed to the rescue, disabling three ICBMs threatening the GDI space station, Philadelphia and finally entering Kane's sanctuary, where he confronted Kane, who then used Umagon as a living shield. After a short fight, McNeil was wounded and apparently shot by Kane, who approached the Tacitus. However, it was the Brotherhood's leader who was wounded, and upon realizing it, he faced the supposedly dead McNeil, who impaled him with a sharp metal beam. McNeil saved Umagon and took the Tacitus, taking both to the Kodiak. Umagon was administered an experimental mutagen antidote developed by Tratos (however, it is found later that her mutation was actually greatly sped up in Firestorm). Her ultimate fate is unknown, but it can be assumed that she died from Tiberium mutation in the end. It is hinted Umagon and McNeil had a love interest which didn't endure since she suffered of Tiberium injuries.
The novelization of Tiberium Wars establishes that he is still alive at the start of the Third Tiberium War. He is one of the main characters of the book, and commands the GDI 22nd Infantry Division throughout the conflict.
Commander Michael McNeil was played by Michael Biehn.
Lieutenant Commander Chandra
Lieutenant Commander Chandra was the second-in-command of field GDI operations and a long time friend of Michael McNeil. He served aboard McNeil's flagship, the Kodiak, and accompanied McNeil during missions away from the ship, such as entering the crashed Scrin craft and infiltrating Vega's pyramid.
Chandra piloted the Kodiak on the day that the events of Firestorm began, when the Kodiak flew through an ion storm (The ship having been upgraded with special shielding from the ion storm's feedback) and was struck by lightning, crash landing it in Northern Africa. Chandra may have perished in the crash, as the frontal part containing Kodiak's command center was ripped off following a collision with a mountain and the subsequent explosion.
Chandra is portrayed by Kris Iyer.
A high ranking GDI officer stationed in the Norwegian Hammerfest base, Jake McNeil was well-known and respected by his subordinates. He was also the brother of GDI field commander Michael McNeil (see above), and essentially worked in his shadow.
In the Nod campaign, Jake McNeil is portrayed as an idealist, envious of the position his brother occupies, a fact which Anton Slavik and Oxanna Kristos used to their advantage in order to manipulate Jake into lowering Hammerfest's defenses for Nod so that GDI's orbital space station, the "Philadelphia" could be shot down, and Kane's world altering Tiberium missile could then be launched later, in the final Nod mission.
However, in the canonical GDI storyline, Jake is killed in action when the Brotherhood of Nod attacked and took control of Hammerfest, a fact about which Kane gloated in a transmission to GDI Commander Michael McNeil.
General Paul Cortez
General Cortez was a high ranking commanding officer, who did not receive much fame for his work during the events of the Second Tiberium War. However, when a large-scale ion storm and atmospheric changes cut off contact between the Philadelphia command station and the planet, Cortez swiftly assumed command over GDI, with his base, the Southern Cross, acting as a temporary GDI command center, until contact could be re-established with Philadelphia. He quickly brought together the Firestorm Taskforce, and siphoned off a young Commander from Project Lazarus to head up the taskforce.
His character has proven crucial to GDI's survival during the Firestorm Crisis. He was decisive and highly responsible, which helped save many lives as well as allow GDI to recover the Tacitus intact from Kodiak's wreckage. His decision making also played a factor when CABAL tipped his hand, when he nearly instantly ordered a full transcript of CABAL's "expose" sent to his colonels and ordered a GDI commander to save Dr. Gabriella Boudreau.
He was also reluctant to accept an alliance with the Brotherhood, considering how just a few months earlier Nod soldiers fought with GDI infantrymen in one of the most bloody wars in history. He nevertheless acknowledged the fact that CABAL posed a far greater threat than Nod when he said "as sweet as the idea of dead Nod zealots sounds, they are only being recycled by CABAL to be turned against us". This alliance has proven vital to success however, and despite Cortez's fears, Slavik's men remained true to the pact.
He was married to Dr. Gabriella Boudreau, but divorced prior to the Firestorm Crisis.
General Cortez resigned from his position as a commander and became the head of the Bureau for Mutant Affairs. Eventually he retired from GDI prior to the events of the Third Tiberium War, as he is mentioned in one of the Intelligence data files during the course of the GDI campaign.
General Paul Cortez is portrayed by Efrain Figueroa.
Dr. Gabriella Boudreau
Dr. Gabriella Boudreau is a Tiberium scientist whose research into Tiberium has led her and her team to work with GDI and the Forgotten. She was the one who originally suggested GDI use CABAL to translate the Tacitus. She took over command of the Daedalus team after Tratos' assassination and is seen by many as his and Mobius' successor. Her team took heavy casualties when CABAL went rogue, but thanks to fast action by GDI soldiers guarding the facility Boudreau was able to escape and contact GDI forces. She eventually managed to translate the Tacitus after CABAL was destroyed, opening up vast quantities of data regarding Tiberium to the GDI. Despite the number of years spent on analyzing the Tacitus, it is revealed in Command & Conquer 3: Tiberium Wars that GDI only managed to decode a message which gave a prophecy about being prepared for an alien invasion "in the future." The alien invasion was later revealed to be the Scrin.
She was last seen in a state of awe over the amount of information revealed from the Tacitus. It is revealed at the end of the GDI missions that she is the ex-wife of General Cortez.
Dr. Boudreau is played by Linnea Pyne.
Director Redmond Boyle
Redmond Boyle (portrayed by Billy Dee Williams) is the acting director of GDI. His original position was the GDI Treasurer, but he ended up being the highest ranking official after the Philadelphia was shot down. Despite maintaining the image of a responsible and honest man, Boyle leads the war against Nod with purely political motivations, which leads to ideological clashes with Jack Granger. Boyle does not hesitate to exert his authority over Granger, often forcing him to lead impractical or suicidal missions or using the Ion Cannon without Granger's knowledge. Also, despite his vows not to interfere with military affairs, Boyle spends much time trying to manipulate the player into disobeying Granger's orders, particularly when he sanctions the development of a Tiberium-based bomb in a last ditch attempt at halting Nod and the Alien invaders.
If the player chooses to use the liquid Tiberium bomb, Boyle is seen as a hero and promotes the commander to General after Granger resigns his commission in protest, as Granger does not wish to be in service to an army that would commit such an atrocity in using Tiberium-based weaponry. However, if the Commander refuses to use the bomb, Boyle resigns as acting director of GDI in order to avoid a trial as a war criminal due to his authorization to use the liquid Tiberium bomb.
In the expansion pack Kane's Wrath it is revealed that Kane used Boyle as a pawn, knowing his interest in liquid Tiberium would prove to be GDI's downfall. He did this by ensuring he survived the Philadelphia explosion by attacking GDI's Treasury shortly before the attack.
General Jack Granger
General Jack Granger (portrayed by Michael Ironside) is the player's commanding officer for the GDI campaign. Granger assumed leadership over GDI's standing forces worldwide after the destruction of the organization's orbital command station, the "Philadelphia". He is an experienced soldier who has not discarded his ideals, and continues to consider the Brotherhood of Nod a threat, contrary to popular opinion. He is also shown to dislike his superior, Director Redmond Boyle, because the latter is a politician who directly interferes with decisions made by GDI's military personnel, and also because Boyle eventually begins to sanction Tiberium-based weaponry, something Granger is staunchly opposed to because of the inherent conflict between GDI's mission to eradicate the threat of Tiberium, and the usage of Tiberium-based weapons in warfare.
If the player elects to use the liquid Tiberium bomb to end the final conflict at the climax of the GDI campaign, the ending shows Granger resigning from his position in disgust, not wishing to work for an army that compromises its own ideals. He also holds the player responsible for the millions of the civilian deaths as the result of deploying the bomb, stating that he would court-martial the player himself if he could, and that he hopes the player will regret the decision for the rest of his or her life. Conversely, if the player elects not to make use of the liquid Tiberium bomb and manages to successfully end the mission through conventional means, Granger remains at his position and states that history will rightfully remember the player's name as belonging to a war hero. He also appears amused by Boyle's sudden resignation in order to avoid a trial for war crimes, for having authorized the use of the liquid Tiberium bomb to the player.
Granger has over 25 years of combat experience, making him a veteran of the second Tiberium War. As with Generals Sheppard, Locke, and Cortez, Granger wears three stars, which may make him a Lieutenant General, but his exact rank is never stated.
Lt. Sandra Telfair
Lt. Sandra Telfair, part of GDI InOps, is an aide to General Jack Granger and provides briefings as well as assistance between missions. She bears a resentment against the Brotherhood, often referring to them as maniacs and propagandists.
She is portrayed by Grace Park.
Lt. Kirce James
Portrayed by Jennifer Morrison, Lieutenant Kirce James is a contact at InOps and is usually the one to brief the player before a mission. Her information sets out the mission parameters before the mission begins and is usually vital to the success in the mission. Lt. James appears in all five theatres of war.
Fifteen years after the end of the destructive Third Tiberium War, Tiberium had covered the planet and humanity was on the brink of extinction. Even Kane could not ignore this fact and proposed a desperate alliance with his GDI nemesis to control the toxic crystal. Another 15 years later, extremists of both the Global Defense Initiative and the Brotherhood of Nod fought each other once more for the control of humanity's salvation to the Tiberium problem named the Tiberium Control Network.
Col. Louise James
Daughter of a First Tiberium War veteran, Colonel James has fought in the Third Tiberium War where she lost her two sons to the Scrin invaders. She blames this however on Nod and Kane since they were the ones who caused the Liquid Tiberium explosion and attracted the aliens to Earth. She begrudgingly followed GDI's orders to work with Nod even though she (among others) believe Kane to be a mass murderer. In 2077 she commands the GDT Tzadik and, by extension GDI's First Fleet.
Col. James still views Nod (loyalist and separatist) as a threat and dislikes her political leader Evelyn Rios for trying to interfere in GDI military affairs and Rios's support for Kane, putting James and Rios into conflict multiple times during the short war with the Nod Separatists. While James will cooperate with Nod, and Kane to a lesser extent, she will not hesitate to terminate the GDI-Nod alliance herself if she believes Kane to have a more sinister plan for the TCN.
She is portrayed by Iona Morris.
General Wesley Riggs
A veteran of the Second and Third Tiberium Wars, General Riggs has been respected among GDI to survive even one, let alone two, Tiberium Wars against Nod. He is a realist however, when Kane approached GDI for an alliance to halt the Tiberium spread in2062, Riggs put in his support of the alliance, earning him political backlash. Nevertheless he would not keep his back turned for long, in case Kane backtracks on the alliance.
By 2077 General Riggs is the supreme commander of the GDI military and is seen to be confident of the alliance and the TCN. However he is torn between supporting his extremist subordinate Col. James in combating the Nod Separatists, and supporting the TCN with his political counterpart Evelyn Rios that already has a tenuous political climate.
General Riggs is portrayed by Tim Dezan.
General Secretary Evelyn Rios
A former employee of the Idris Corporation, Evelyn Rios rose up to become GDI General Secretary (the position replacing that of the Director from 2047). Despite the shaky political climate, Rios confidently supports the alliance with Kane and the TCN unlike many in the GDI military and populace. Rios is determined to preserve the fragile democracy of the last old superpower left on Earth, and attempts to assert her authority over the GDI military. This particularly irks Colonel James, who Rios also dislikes because of her aggressive actions to combat the Nod Separatists and maintaining the TCN without causing civilian casualties. This comes to a head when James launches an insurrection against Rios due to the latter disregarding James' belief and evidence that Kane has a more sinister motive.
Rios is portrayed by Nastascha Roi.
Sergeant Nash is a NCO and serves onboard the GST Tzadik alongside Col James. Nash holds high regard for the player, having saved the GST Methuselah from crashing in which Nash was on board at the time of the Separatist attack.
He will support and guide the commander in his missions if the player sides with GDI. If the player joins Nod, the player will be battling Nash on several occasions.
He is portrayed by Caleb Moody.