The military haven't used airships since the 1930's because transatlantic aeroplanes rendered them obsolete. Not because of some military-industrial complex conspiracy.
Every couple of decades the DoD decides that blimps are back in fashion and throws millions of dollars into blimp projects. Inevitably they cancel the project and decide they don't want them. Admittedly they've all been helium, but the reasons for cancelation are usually related to capability and the intrinsic qualities of lighter-than-air flight, and not cost.
The past 20 years, they tried Integrated Sensor is Structure (USAF) [1]; Long-endurance, Multi-intelligence Vehicle (Army) [2], Blue Devil (USAF) [3], Walrus advanced technology demonstration (DARPA) [4], and a handful of other boondoggles [5].
If anything, the concept of viable airships in the 21st century is just a defence contractor gravy train.
Every couple of decades the DoD decides that blimps are back in fashion and throws millions of dollars into blimp projects. Inevitably they cancel the project and decide they don't want them. Admittedly they've all been helium, but the reasons for cancelation are usually related to capability and the intrinsic qualities of lighter-than-air flight, and not cost.
The past 20 years, they tried Integrated Sensor is Structure (USAF) [1]; Long-endurance, Multi-intelligence Vehicle (Army) [2], Blue Devil (USAF) [3], Walrus advanced technology demonstration (DARPA) [4], and a handful of other boondoggles [5].
If anything, the concept of viable airships in the 21st century is just a defence contractor gravy train.
[1] https://en.wikipedia.org/wiki/Integrated_Sensor_is_Structure
[2] https://www.ainonline.com/aviation-news/defense/2013-02-22/u...
[3] https://defense-update.com/20120529_blue-devil-2-airship-def...
[4] https://www.flightglobal.com/darpa-details-plans-for-ultra-l...
[5] Congressional Budget Office, "Recent Development Efforts for Military Airships" (2011) https://fas.org/irp/program/collect/cbo-airship.pdf