Well, in my opinion, there are few, if any, simple actions that can really change both these complex problems for the better. We have argued back and forth about this for awhile by now.
So now we have President Trump, doing just as he had promised. Applying a simple solution to some very complex problems. And now we're learning what the consequences are! Many good people are prevented from traveling in and out of the U.S., for example. Students cannot return to school here, employees cannot return to their jobs, and family members are suddenly isolated from each other.
So perhaps we needed this. An 'in your face' demonstration of what happens when you try to apply simple solutions to complex problems. So that everyone can see what happens in real time. So that everyone can see why trying to run a government for a country of 325 million people, in today's complex world, is a very complicated affair indeed!