You are pushing it quite a bit for me to say that tariffs are morally ethical with very unrealistic situations… however, since we are starting from assumptions: my economy would be so diverse and decentralized that I would not have a single supplier for my resources: if this happened to me it would not affect me so much and it could not be used as political blackmail (the case of Switzerland, saving the distances with the case you put)… I repeat: with tariffs only mediocrity is rewarded and expanded, rewarding the inefficient and leading citizens to poverty, forgetting that there is a redistribution of work and forcing citizens to pay more for goods and services… applies to China, the USA, the Faroe Islands, San Marino, etc