Look at the bark on this one. Good comeback.
Isn't it an odd comparison between taking the mainland when nobody was around and a heavily-manned Pentagon? One has the Enclave fighting mutated creatures and other such things, the other has them fighting a group of well-trained, well-armed Brotherhood men.
Not really. Technically, taking over circa 10 years after the Great War would be insane easy compared to say, what Caesar did what? In the 20 or so years leading up to NV.
Mutations would have been minimal. In fact, had the Enclave isolated the FEV off the get go, there is no Master, and no Mutant army.
BoS would have been small. Enclave could have recruited people from Vaults, including Vault 15 which would have eliminated the Khans, Vipers, Jackals, and Shady Sands, thus the NCR.
Boom..Enclave nation.
I'm just saying if it "easy" to take the Citadel, it was just as easy to get off their butts and take over in 2082 when there was no opposition, and they had resources(Vaults) to leech from.
But, they didn't. Obviously for whatever reasons they didn't take over, and they didn't attack the Citadel. As LT pointed out, Enclave have been fairly ineptly written since conception. In fact, at least Beth was consistent with Enclave being fairly durp durp.