Insanely, the Chicago Convention of 1944 exempts international flights from any fuel tax. https://www.icao.int/publications/pages/doc7300.aspx

Various attempts to work round this without rewriting the convention have been discussed, e.g. https://commonslibrary.parliament.uk/research-briefings/sn00... but I don't think they've got anywhere.

The US _might_ be able to tax fuel on domestic flights, but that would result in the California to Seattle flight going via Canada to avoid the tax.

Part of this has a decent reason: If fuel is much cheaper in e.g. Dubai, airlines will chock their planes full of fuel instead of the optimised amount, leading to overburning of fuel due to excessive transportation of it.

And the opposite, they will skimp on fuel going inbound to there. Of course fuel qty is the captain's decision, however a lot of airlines already pressure those. As one example Ryanair had a "list of shame" of captains bringing too much safety fuel in their eyes.

The idea that airlines can pressure captains in to doing _anything_ is terrifying and should be utterly outlawed.

If you consider the per seat cost compared to commercial, I don’t think making it a bit more expensive will move the needle.

Exactly. And the old story of "oh well the rich will take their money elsewhere" won't work. They need to stay in the US, that's the whole point.

Maybe there will be a point where it works out cheaper to fly to another country to fuel up though. I'm sure some tax policy folks could figure this out better than I.

Tax the ~~rich~~ ultra-wealthy, and their thoughtless damage to our environment. It's about as close to a victimless tax-rise as could ever exist.