The Constitution Preamble is global, there you can also interpret that even international policy is involved, because it clearly says ''...<em>provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity''.</em>
So, the actions that can be taken to ensure defence and welfare could be a lot. That's guy in the name of National Security the U.S participated in other countries issues.
You could probably figure out that the boys in the story are English schoolboys, and were more than likely being evacuated from their home country to escape the possibility of atomic warfare. (Does this help?)
