Nobody with interest in politics thinks it's about drugs. It's a pretext and a way to gain legitimacy to exert force over foreign nation with some legitimacy that would otherwise clearly go against international law.
Although it is 'heavy' oil, the 'brown coal' of liquid fossil reserves (i.e. low quality).
The fact that such a fuss is being made about low-grade oil is a concern in itself.
Keep in mind there's a lot of 'idle' refining capacity at the southeastern coast of the US which was built for heavy oil.