Very limited use nowadays as Protocol III of the Geneva Convention on Certain Conventional Weapons prohibits the use of incendiary weapons on people. You can, however, use them to clear foliage.
Napalm also banned, has been for years.
It seems that napalming or flame-throwing dug-in troops is frowned upon, and just not cricket. Neither is gassing them.
However, artillery fire missions (inc MLRS-types), B-52 carpet bombing missions, direct engagement with tank main weapons, grenading the poor bastards, mortaring them, and even small-arms engagement as a last resort is "game on".
I recall seeing a TV news item several years ago of the California National Guard using flamethrowers in a very large park to burn off an illegal Marijuana plantation.
I hope the guardsmen were issued respiratory protection.
Then again, being California they may all have been taking deep breaths.
FFS man,... don't go putting ideas into their collective dense brains, its bad enough they have limited access to military style hardware, can you imagine what carnage a southern red neck would cause in a shopping mall with a flame thrower............... .
The same carnage as a UK citizen would do if they had one? I take it you forget about what happened at the school in NI when a disgruntled ex student paid a visit with his home built version in the early 90’s.......
IIRC from my research some 15 years ago into the Malaya Emergency, flamethrowers were used to clear foliage at the side of the narrow roads to reduce the ambush risk (most TICs were at less than 5 yard range); similarly there's a worrying-looking file in the National Archives marked "Chemical Warfare" that referred to the use of airborne-delivered defoliants used for a similar effect. About 15 years before Agent Orange. Just saying...