In brief, the state cannot tell anyone who they can or can’t do business with except under very specific circumstances laid out in depth. The President can’t merely forbid entire countries, including his own, from trading anywhere since this is all private property. Sanctions must set out a reason, the nature of the trade itself described in detail and the affected objects connected with the stated purpose of the sanctions. Each object affected by the law has to be closely connected with the purpose of the sanctions. Since corporate America is legally more powerful than the Justice or Treasury Departments, companies usually can evade these without fear, though compliance costs might be absorbed as insurance.