I don't think the straights are so dire....
Read the following; there are professional historians who disagree with you.
Blog Them Out of the Stone Age › Hand Wringing for Military History
Also, as for why the geographic concnetration your perceive?
Well, because the subject is of interest in those areas.
And while you have talked about War Studies did you also look at the field of naval history? It has a robust following in New England academia.