Perhaps, you did not realize it but most nations have signed a treaty to ban gas-air weapons on the battlefield. This is as they are so deadly, and a single aircraft can fly over a battalion of troops on the ground and deliver a fiery inferno leaving them crispy critters and chard beyond recognition. Seems like hell on Earth, you say? Yes, that’s a fantastic way to describe it, and you certainly would not want to be on the losing end of this game. Incidentally the United States didn’t sign the treaty.
Why you ask, well, we are the inventors of Napalm, and the more modern versions of gas-air weapons, which are even more lethal than previously, also more accurate, truly scary stuff, and if the 1000-degree and fire will not kill you, all the oxygen is sucked into the fire so that you suffocate, either way you have no escape. Even nations refusing to sign the chemical weapons ban sign were worried about gas-air weapons from the sky.
Today, we could easily deliver those lethal munitions from UAV (unmanned aerial vehicle) or drone. Again, scary stuff, but let me tell you of an even scarier potential invention for robotically dropped gas-air weapons using swarms of UAVs constantly refueling the weapon pods using aerial refueling and unleashing this hell for hours on end until there are no enemy infantry anywhere.
To begin with, I suggest having a pod of polymer balls that expand when filled to 2,000 times their initial size. They will be filled with a liquid fuel-explosive mixture, along with the polymer balls un-expanded will sit within the pod and after the gas enters the chamber”x-amount” of balls will be released and like a membrane sponge soak up the fuel until the inside cavity of the pod is stuffed. The liquid-fuel volatile will be transferred into a reservoir in the UAV, the UAV will then search and strike accordingly within a swarm of 100s of other UAVs.
Once depleted of polymer balls and gas that the UAV will fly back up to the appropriate elevation and meet up with the airborne re-fueler and repeat as long as necessary, perhaps days? Yes, I do have drawings, drawings and schematics and in case you have a security clearance, then come look me up. Nobody wants or enjoys warfare, but if you end up in one, you have to acquire, and decisively. Such a weapon is sure to break the will and moral of any infantry of any enemy. Please consider all this and think on it.