There are two premises (in order). 1. The US wants Saudi Arabia to become a liberal democracy (the end) 2. The US thinks that doing this can achieve that end

There are two premises (in order). 1. The US wants Saudi Arabia to become a liberal democracy (the end) 2. The US thinks that doing this can achieve that end (the means) I see no reason to accept (2) and moreover no reason to accept even (1).