While tens of thousands of people have joined Facebook groups in Sweden and Denmark calling for no longer buying American, Norwegian company Haltbakk Bunkers has announced that it will stop supplying US military vessels with fuel.
If you want to learn how to do successful boycott campaigns, you should look for the BDS Movement, that has worked to spread awareness to boycott companies affiliated with the illegal Israeli occupation and genocide against Palestinians.
And no surprise, you will find many US companies in there. Also it should come as no surprise, that the US wants to outlaw even talking about boycotts in many states, as well as corrupt European politicians like in Germany attacking the notion of boycotting companies involved with brutal crimes against humanity.
We need to join efforts in reducing the economic power of Imperialism, whichever shape it takes.