What should U.S. response be to the downed Malaysia Airliner Flight 17?

Our response should probably be just what it is, controlled and cautious on the face of things, while doing all we can diplomatically and politically behind the scenes to assist the recovery and impending investigation; as senior U.S. intelligence officials state they “have no evidence of direct Russian government involvement” in the incident, and investigators believe this was the result of a missile, mistakenly fired by separatists. World leaders are demanding a full-scale investigation; pro-Russian separatists have shown little willingness to allow it, and President Putin says he will put pressure on the rebels to investigate, though Russian media is supposedly blaming USA/CIA and Ukraine for the incident.  Such “investigations” can be lengthy.  On July 3, 1988, the U.S. Navy, guided-missile cruiser USS Vincennes, shot down Iran Air Flight 655 civilian passenger plane over Iranian airspace in the Persian Gulf, killing 290 people (66 children and 16 crew).  President Reagan responded by saying that “the Vincennes had taken proper defensive action”.  It took four years for the administration to admit that USS Vincennes was in Iranian waters.  In 1996, an agreement was finally reached on the suit brought by Iran to the International Court of Justice; the U.S. agreed to pay $61.8 million, plus the cost of the aircraft and legal expenses.  “The U.S. government expressed regret only for the loss of innocent life, and did not make specific apology to the Iranian government.”