id say the most likley culprit is the air lines them selves

they might have devised an addative that extends the combustability of the fuel
meaning they dont need as much of it ,saving money
its most likley illigal and toxic but for profit most wont care as its hard to prove...

imo htis is more likley then the whole govenment stuff as the airlines are big buisness who have a track record of not giving a shit when profit is involed

for it to be government it would need to be politically driven ,im sure contrys like russia would just love to "squeal" on them lol