So you are a physicist in the US, and you're having a casual conversation with a bunch of new physics graduate students. When you ask them what they intend to major in (a very obvious question to ask in a situation like this), some of them say "I want to major in high energy physics".
What do you say in return? Do you just say "Well, good luck!" and leave it at that? Or do you feel a sense of responsibility to tell these students of the prospect that they will face here in the US for someone with that major?
This issue is nothing like the issue with students wanting to do "theoretical physics", because these students, presumably, a smart enough to know the area that they are going into. However, while they have a good idea of the nature of the subject matter, they have very little idea of the funding, job prospects, etc. of those people who graduated with that degree. And for HEP, the outlook is even bleaker than a lot of the other areas in physics for someone who wants to have a career in that field. The US funding for HEP has consistently been cut year after year, and especially more so after the Tevatron at Fermilab shut down. While many in the US collaborate on work done at the LHC, funding for the HEP division of DOE's Office of Science continues to shrink, and it doesn't look any better in the future.
So, knowing all this, what would you say to such students? Do you try to persuade them to change their minds and tell them that it is not to late to switch to a different field of physics? Do you lay out the reality of the situation? Do you tell them that if they still wish to continue, they need to be prepared for the possibility that they will not be able to pursue a career in such a field?
In my case, walking away and not say anything is not an option. I somehow feel some level of "paternal" responsibility towards these kids, and I can't just let them go into something blindly without at least giving them some dose of reality. Whether they listen to it or not is an entirely different matter, but at least I tried.