It is interesting to see the trends in Hollywoods war-movies.
Early on, in the 40:ies, it was much about glory, heroes and doing wath's right.
In the 60:ies many movies that said, "war is bad, but what's even worse is athourities". Examples of these are, "Bridge at Remagen", "The Dirty Dozen" and "Kellys Heroes". The soldiers knows best, discipline is for sissies and officers are ridiculed.
Later we saw movies like, "Apocalypse Now", "Platoon" and "Full Metal Jacket". Their message was in a way, "war is insanity".
It's hard to label the war-movies of today, but one thing i certain - the glory is back. "Saving privat Ryan", "Black Hawk Down" and "We Were Soldiers" to name a few, all held duty and heroism high.
Feel free to fill the gaps
The conclusion, as many have mentioned, is that Hollywoods primary goal is to fill movie theaters. The movies says, in a sence, more about the society at the time they were released, and less about what historically actually happened.
There is two movies about war that gave
me a feeling of realism: "Tuntematon Sotilas" ("Unknown Soldier") and "Talvisota" ("The Winter War"), both Finnish movies.