Mr. Bloggs,
In India I am tested before almost every flight. In 19 years of airline flying in the US I was alcohol tested exactly 6 times. Two of those were post flight after 6+ hour flights. All that I was saying is that if the rate of testing in the US was as high as it is in India I believe that there would be a higher rate of positives. I think the attitude to alcohol use and flying is better in the US but that with the sheer volume of pilots and flights I believe some pilots that are operating today could not blow all zeros in the morning. Some people cut the time from last drink till show time precious close knowing that the odds of being tested are vast. This is just my observation. I believe that the overwhelming majority take their resposibilty very seriously but we all have known people who push the envelope.