Actually it should be a simple as expiring whatever API key the jets use to communicate back to the US-based control servers. So when it POSTs to a StartEngine endpoint or whatever, it wouldn't start.
Apart from war machines communicating through HTTP, I can't help but giggle to the thought of such a dialog:
- I repeat, the enemy seems to be not responsive.
- What, you already killed them?
- No we came with a bigger force but their layout didn't change. I don't think they're war-scale.
Joking aside, there's nothing making HTTPS inherently less secure than any other secure channel out there, right?
No government would buy unreliable weapons.