but they do something to the oxygen around them and it'll make them suffer :(
Thermobaric weapons use the oxygen around them to detonate. So basically there is no oxidizer in the weapon, so it is all explosive. It creates a vacuum when detonated, and a fireball with a duration second only to a nuclear bomb, but not on that scale though. Thermobarics are much smaller than a nuke.
Oh btw you'll be pleased to know the main killing mechanism is the pressure change which ruptures people's lungs.
If this gives you moral qualms then consider that France killed hundreds if not thousands in a nuclear attack on Swiss soil.