GDI Mission 05: Repair the GDI Base
Play time: 27:33

The GDI has secured Poland and most of Belarus, but Nod has managed to conquer all of Germany, Denmark, (Schleswig-Holstein )), Austria, and Romania, and Bulgaria, and advanced further into Ukraine.
Nod spread fake news about GDI war crimes in Eastern Europe, which resulted in a suspension of all GDI funding while investigations are going on. Which means GDI forces have to make do with whatever they have currently in the field. The objective is to secure and repair an abandoned GDI base in northern Germany.

The starting troops include two Medium Tanks, which look quite a lot like M1 Abrams, the standard US Main Battle Tank. The base has no Construction Yard, so you can't build any new buildings, but the forces Nod sends against it are no real threat. Fortunately the Refinery still has a harvester and there's a decently sized tiberium field right next to it. You have Barracks, a Communications Center, and also a Weapons Factory, which lets you build Humvees and APCs, but I mostly went with more machinegunners and grenadiers. Once the air defenses outside the Nod base are destroyed you can get air strikes again, but this time it's only a single A-10 instead of three, which makes the whole thing pretty underwhelming.

Pretty easy mission again.

Nice idea to have Nod sabotage GDI by targeting public opinion, but this raises questions of what GDI actually is. I assumed it to be some kind of NATO+, where the member nations pool together their military forces. But I don't quite get why they would end their alliance while Nod is steamrolling through Germany and Austria.

GDI Mission 06: Infiltrate Nod Base
Play time: 7:48 (probably 45 to 60 minutes with loading)

GDI has retaken Dennmark, Schleswig-Holstein, Germany, and Ukraine and pushing into Chechia. There's only a garbled message from the front about infiltrating a Nod base.

Here you start with only a single unit. The Commando. He can blow up buildings with explosives and has a silenced rifle with pretty long range, but he can't damage vehicles at all. After the first two air defense sites are destroyed, you also get a Chinook transport helicopter. Today it would be an Osprey, but I believe that was the default helicopter for such things in those days. The Chinook has a huge vision range, which is a massive help.
Sneaking through the outer defenses and sniping guards and blowing up missile sites is pretty easy, but the main base is a lot tougher. When you take out any guard or building, all the troops guarding the base come running. This actually makes for a really good diversion and you can hop your commando into the helicopter, quickly fly around the map, and drop him at an unguarded gate. Easy in theory, but with the commando having little health and no option to heal him, it really is a lot trial and error. Not having clear objectives also sucks. In the end I just tried to run away from the tanks that were coming and when I got into a dead end I just blew up the Nod airstrip next to me. It exploded just before the Commando was getting shot by tanks, and that somehow successfully completed the mission.