Big weapons deals are always deeply political. If you have a defense alliance, it affects where you buy. South Korea, Japan and Australia, etc. can generally b

Big weapons deals are always deeply political. If you have a defense alliance, it affects where you buy. South Korea, Japan and Australia, etc. can generally buy any big weapon system they want as long as it's American, because the US has huge political commitment to defend these countries. They can take bids from others to keep the price/performance within reasonable limits, but unless the US system is outrageously expensive or inferior, they go with that.