Very easy to change with laws. Similar to how laws were passed after 2008 to force banks to be less profitable (they can't trade any more, need more reserve capital, etc.). Very easy, all you need is political will. Trump was going in the right direction with trade war with China (possibly for the wrong reasons), I'm really happy because I predict it will be a political suicide for the Democratic candidate to propose the opposite policy now, so it will become the policy regardless of who wins the election.