Why not Blimps?

In Akron Ohio there is a Blimp hanger owned by Lockheed Martin since 1996. It was used in WWII for Goodyear Blimps production. Lockheed has a $149 million contract with the Pentagon to build a prototype Blimp which will hang 12 miles up for months, unmanned. It is being made to monitor communications. The prototype is 400 feet long and 140 feet in diameter. A two line tether could be used and smaller Blimps to mount cameras on the blimps to watch the Mexico border. How much does 6000 national guard troops cost tax payers compared to hi-tech answers. BTW, I would be happy to Monitor one camera from my home, I work cheap.
Jack09