Could someone with expertise explain the legal reasoning behind the arrest of Meng Wanzhou? When the U.S. declares sanctions against a nation (Iran), does that mean that anyone in the world who doesn't obey those sanctions is subject to extradition if they visit the wrong place?

Because, if so, i totally don't get that. Those sanctions are just a U.S. law, right? How can someone in another country be guilty of violating a U.S. law that doesn't apply in other countries? (Yes, I realize this case is a power politics game, but legality still matters.)

I feel like there must be *some* legal angle to this that I'm just not getting, because so far none of the news reports I've seen (hmm, all U.S. media though) have commented on the jurisdictional question that I would have thought would be foremost here. What am I missing?