The final attack on Cairo is the final stage of GDI's covert campaign in Egypt to neutralize Nod's WMD program. It's all the more important seeing how Nod will launch everything they have once they realize the complex is under attack.
The facility at Cairo is Nod's most important military base worldwide, with the exception of Temple Prime at Sarajevo. Kane has secretly concentrated his nuclear arsenal at this location before the war, camouflaging the installations under the desert landscape. After the destruction of the Philadelphia by this same base, they were removed and launching transferred to a single central platform, improving launch times. After destroying Nod's Tiberium research program in Egypt and razing their WMD distribution center in Casabad, the time has come for GDI to end Nod's nuclear capability permanently.
This Walkthrough assumes Hard Difficulty Setting.
You start out with not much, a few basic structures etc, a couple of Predator tanks and Zone Trooper squads, and you're there to destroy the largest Nod installation you've seen so far.
Start off by building a crane, then simultaneously build a War Factory and Air Field, with your air field placed preferably on the northwest corner of your base. The nuke silo will show up soon enough, with a six-minute countdown. Once the air field is done, order an Orca strike on the nuke silo, then queue up four Orcas on your aircraft tab and a few extra Predators. Once the power plants on your optional objective gets revealed and you have a full airfield's worth of Orcas, send your Orcas, to the Anti-air defense free corridor west, all the way up until you reach the blue tiberium field and Tib spike. Now turn your Orcas east. They'll soon come under fire from Nod SAMs, so just destroy the SAM hub near the westernmost Nod Power Plant. Once done, micromanaging your Orcas is key; get them back the same way you got them in, as their automatic rerouting will lead them straight into a no-fly zone. Blowing up one power plant will shut down the timers until another gets rebuilt. Make sure it's your second nature in this mission to blow up the power plants the same way when the nuke silo timer goes back on. Oh, and by the way, the Nod forces will not bother that corridor, ever, so feel free to put a surveyor and a refinery up there to boost your economy.
Now you know how to disable the nuke silo. Time to build up your forces. You've probably been attacked by convoys of Nod vehicles by now (composed of Attack bikes, Raider buggies, Scorps and Flame tanks) and mobs of militants, but they're no problem, really. Just hold your line with Predators and you'll do fine while you build up your Tech Lab.
Once you get Mammoth tanks rolling into the battlefield, take over the blue tiberium field at the southeast corner of the map with a surveyor and refinery. If you take over those tiberium fields, you'll soon have a hard time counting how many Mammoths will roll over the Nod forces.
This mission is all about being cool under fire, and steady micromanaging until you get your Mammoth tank armada running. The nuke silo will fall under three full orca bombing runs (and all of them will survive the missile-saturated no-fly zone long enough to fire their payload) and continual takedowns of the power plants will derail Nod's nuke timer. This is really just an intimidating, yet a pretty easy mission. Your only real problems are completing the Intelligence entries in the database.
The destruction of Nod's nuclear launch facility dramatically reduced Nod's military capability. Nod could no longer repel the GDI assault into Yellow Zone Y-1 without their weapons of mass destruction and had to look for weapons elsewhere - capturing GDI's own nuclear arsenal in Australia. Though this would not occur for some time.
News of GDI's covert operations in Egypt had leaked to the media, which were previously suppressed to prevent more panic arising from the Blue Zone populations. The media even speculated that a new Nod Temple was secretly constructed in Sarajevo upon the ruins of their own temple destroyed back in the First Tiberium War. While the GDI military was already aware of this, Director Boyle was not and had been left to fend off the media questions in a press conference. Afterwards he and General Granger were at loggerheads as Boyle proposed a new campaign to destroy Temple Prime.