I'm pretty sure the Global Hawk UAV was around during the time. DOD and DARPA were futzing with several different UAV designs during the 90's, I believe Paul Mulcahy has a section on UAV's that might have been used during the Twilight War.
As AvGas becomes more scarce, I think UAV's might become more popular, particularly smaller lighter ones that is, that could run on electric or alcohol fueled motors. Also, I don't think it would be unrealistic to jury rig various weapons (within reason, of course) onto these UAV's, like they did with earlier versions of the Predator that were outfitted with two Hellfire missiles before they came out with the more heavily armed UAV's like they have now such as the Reaper drone. Even then, if it's only carrying cameras, that will still be a huge boost as real time reconnaissance on any battlefield is critical, especially if you have reduced recon assets to work with.
Then again, a lot of this IMO will slightly depend on what timeline your particular T2K scenario takes place in, as I know there's a few alternate timelines out there. There is a T2k module called "Airlords of the Ozarks" that dealt with New America that I have on PDF, it talks about dirigibles and 1-man light aircraft that consisted of a glider, frame and motor (forgot the damn name) that were used, if these were to also be unmanned, espeically with the dirigible equipped with cameras and a plethora of weapons, THAT would be admittedly VERY cool.
