Citing intelligence, Washington and its allies said an accidental missile strike by Iran appears to be the reason Ukrainian Airlines Flight 752 crashed this week near Tehran, killing all 176 aboard. But Iranian officials have dismissed that explanation as "a big lie," demanding the U.S. and Canada release evidence to prove it. They've also invited the U.S. National Transportation Safety Board and Boeing to help investigate the crash.
What's next? Proof the 737-800 was shot down could turn public opinion in Iran against the government, especially given the simmering discontent over its crackdown on recent protests.