like you said, napalm's 1940s tech, lets have some new gear here please
M202A1 FLASH, a 4 round, reloadable 66mm incendiary rocket launcher, has about a 750m range bursting TPA (Thickened Pyrophoric Agent, in this case Triethylaluminium) that ignites on contact with air over an approx 20 meter radius with a burn time of about 8 to 9 seconds at 1000'C. The Russian developed weapons akin to this in RPG/recoiless rifle layout, all combat tested in Afganistan, Chechina etc
the above are used like any incendary, ie WP (White Phosporus) now that we're not alowed to directly burn the bad guys, we throw WP 'smoke' grenades at them, their fault if they stand too near and get burnt to death, neither WP (available in large caliber shells, grenades and RPG rounds) are considered legally to be anti personel, but are always unofficially used as such in the field
now, try this one: think of the word 'thermobaric' you know what that means? while it might not sound like 'burning men to death' like the term FAE (Fuel Air Explosive) both are actually bombs far more efficent than napalm ever was, by almost atomising the fuel they contain in a controlled explusion/explosion then ignighting it, the entire section of air/land soaked by this fuel vapour literally ignites and the blast wave is
huge
if you are in an area where the very air sets aflame at 3,000degrees, you're double screwed, the only place to hide is underwater, not good out in the field/desert, then there's the overpressure blast at about 30 times atmospheric pressure moving at around 10,000 feet per second, nowhere to hide...
again, technically theyr'e an anti material/fortification tool, as burning men is a no-no, but if they're in the area when it's dropped, well, sucks to be them
napalm and flame throwers are out dated, you can get WP and thermobaric rounds for even your classic RPG7, it fires further than any flame thrower ever will, equally FAE is far more efficent and lighter to transport via plane, so more effective on target, the thermobaric burn and suck/blast wave is creates is devestating, a mini-nuke in effect
so, napalm might not be allowed, but FAE, thermobaric and WP/smoke rounds are, give it a nice name and techincal description and you're there, remind ppl of burning children in 'Nam and your'e not..
edit -
link. seems i remembered my stuff from the various sources i picked it up from - when they say 'flamethrower' about th RPO-A they mean incendiary rocket launcher