““Those that gave the passenger plane clearance to fly through a war zone are ultimately responsible.””
The American Federal Aviation Administration issued restrictions on flights over Crimea, to the south of MH17’s route, and advised airlines flying over some other parts of Ukraine to “exercise extreme caution”. This warning did not include the MH17 crash region.[62][6337 airlines continued overflying eastern Ukraine and about 900 flights crossed the Donetsk region in the seven days until the Boeing 777 was shot down, with Aeroflot, Singapore Airlines, Ukraine International Airlines, Lufthansa and Malaysia Airlines being the most active carriers.[64]
https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_17
FAA has little standing with foreign carriers and foreign, non-contiguous to US airspace.
Foreign carriers should have listened, though.