There was a time when the U.S. government actually opposed firing on civilian aircraft. That provision became a problem in 1994, when Peru and Colombia announced that they would start shooting down planes suspected of carrying drugs. To preserve U.S. cooperation with those countries, the Clinton administration backed legislation shielding federal employees from criminal prosecution and civil liability for participating in drug interdiction efforts that included attacks on civilian aircraft. Opponents of the legislation warned that it invited just the sort of incident over which U.S. officials are now wringing their hands. By passing this law, we will encourage Colombia and Peru to become more aggressive in implementing their shootdown policies.
Accidents happen all too often without American encouragement.
Before you answer, consider that drug traffickers merely facilitate what the government is trying to prevent. If the people who actually use drugs deserve only light punishment, it's difficult to understand why the people who assist them deserve to die. Without the demand generated by those who like to snort or smoke the stuff, no one would be flying cocaine through Peruvian air space. But as long as people want to use cocaine, there will be people to supply them with it. But because there are so many places where coca can be grown and so many ways of getting cocaine to American consumers, interdiction will never have a lasting impact on supply.