I don't think that there has been a decline of morality in the US at all. The fact is that the "good old days" never existed. There has always been good and evil, and there always will be.
Wars and "terrorism" have existed long before now. There is a lot of good going on, if you look for it. If you look for negativity, you'll find it as well.
I have no idea how the US will be in 100 years, but I believe that the good/evil balance will be about the same as it is now and has always been.
America is seen as a one Continent, with two subcontinents((North America and South America); or 4 Geographical Regions (North America, Central America, South America and the Caribbean) or 2 Cultural Regions (Latin America and Anglo-saxon America, -Instead of "North America and Latin America" since we are talking about the LINGUISTIC origins of their population-). See America.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.