There's no nice way to say this so ...
THIS MOVIE IS BORING !!!
reason #1 : The premise of the story is boring. The Arlington Honor guards during Vietnam ? I'm sorry, but that's boring. There are so many other aspects of Vietnam which can be made into a movie - and you make one about the Arlington guards who bury the killed Vietnam vets ? Even a movie about a guy who goes over to Vietnam to be a DJ (Good Morning Vietnam) was more interesting than this.
reason #2 : James Caan cannot carry a movie. He can't. He's not a lead actor. He's a decent supporting actor - boring lead actor. If you don't beieve me, then watch something like Rollerball or Thief. Now, before you say something like "I loved Rollerball", try to think about how much better it could have been with so many different actors in the lead role.
reason #3 : DB Sweeney is a horrible actor. He's bland & he has no screen presence whatsoever in any movie he is ever in. He got a bunch of key roles back in the late 80s / early 90s. Then everyone realized how boring the guy was. That's why he doesn't get any more key roles.