How do they justify buying US war tech? By understanding what the US will do to their country if they don't buy it, and figuring out how to sugar coat this to their populace.
This simply isn't true. Various countries bought F-35 even after recognizing it's far more of a geopolitical PITA than Rafale or Gripen because F-35 is world-beating. It is that much better than the competition that putting up with various restrictions is almost always worth it.
Where the competition is less slanted, yes you see countries selecting Leopard for their MBT over Abrams (the US won't sell the advanced Abrams armor packages). But when it's F-35 vs. literally anything else, the competition is for second place. You only really choose something else when F-35 isn't an option at all. Threats aren't needed when you just have to do a fly-off.
But is that really how nations decide which plane to buy?
Sure, technical capabilities are crucial, but don't political and economic factors significantly influence the adoption of the F-35? Factors like strengthening alliances, diplomatic influence, cost sharing, job creation, and export strategies.
My point is: you don't just buy a plane. You buy into an ecosystem where supply chains, political partnership, trade deals and long-term support are just as important. Take away some of that, and I'm sure for a lot of buyers the Typhoon or Gripen suddenly start looking a lot more attractive.
The F35 is better, but they're not going to trust or give business to the US anymore. The Typhoon, Rafale and Grippen are good enough, so we'll see more purchases of those.
Countries do have choices and many did choose the us as security provider. Some thirld world countries recently switched away from russia and/or started to built versions of their own design of previously in license produced weaponry. Examplw: India
And Turkey buys from both. But India and Turkey have a degree of independence that small European nations do not have. The latter are entirely reliant on NATO for their security, and until recently this meant being friends with the USA.