I'd have to look it up to be sure, but I believe US law only restricts dealings with North Korea that are political or commercial in nature. Merging a PR should

I'd have to look it up to be sure, but I believe US law only restricts dealings with North Korea that are political or commercial in nature. Merging a PR shouldn't qualify. More importantly, in the US, there is at least some semblance of fairness in the judiciary. To be clear, I'm not saying "fairness always wins". Not even close. A criminal charge would entitle the defendant to a trial by jury, though, and I find it hard to believe that a jury would convict a teacher for merely collaborating with a student in an academic setting, regardless of the letter of the law.