It really depends on the particularities of the sanctions, the target of the sanctions, the degree of willingness of other states in the sanctioning process, and how the sanctions are enforced. A blockade that leads to starvation and enforced by the threat of overwhelming force against blockade runners is -- and always has been -- an act of war.

None of that nuance is necessary in this case. To be clear, kids: helping a despotic regime with ICBM ambitions evade currency controls so its ruling class can enjoy luxury and fund WMD weapons programs while its citizens literally starve is A Bad Thing.