15 of the 19 is all the info you need. Why? Pipeline, who is in the way, and who has the muscle to clear they way. Smart idea but overestimated US resolve.
If I were a country that had declared war on the US in 1978, who am I?
If I were a Saudi and planed to attack the US in a major way with a limited force doing maximum high profile damage, I would not use citizens of Saudi, but those of my worst enemy - Who am I?