It appears you have set up only one shipping rule for All Countries that looks up the USPS Express Mail rate, and you have two more rules for US destinations looking up the USPS Priority Mail and USPS Cheapest (comparing First Class vs. Priority) rates. Thus, buyers in the US will only be offered Priority and (if available) First Class rates, and buyers in the rest of the world would only be given an Express Mail rate.
We would recommend deleting your two US-based shipping rules, then create two more rules for using the USPS Cheapest and USPS Priority calculation methods, applied to All Countries.
