I'm not as optimistic as you are. The RATS have taken the head in the sand approach for political expediency, not unlike McClellan amassing the largest army and not using it.
We are in an epic battle between modernity and barbarism. We will either civilize the barbarians or we will have to fall back to the Americas and the second position seems to be the popular position.
Your not wrong about the epic struggle we've found ourselves in. It's a struggle that's been underway for generations. Now, our generation has been called to serve. My point about living the legacy of Lincoln, Grant and Sherman is really about momentum. The world used to be a far darker place. Now, there are only shadows of barbarism. To your previous point, it's not that our more liberal American compatriots don't agree with liberty and justice for all, rather they've abandoned the context by which righteous things are born in a barbaric world. They take Western Civ for granted the same way all adults take for granted that they were children once, and therefore behaved childishly. The broad reality is; the ideas America is founded upon are universal. That is the legacy all Americans take with them into the future.
In regard to our generation's duty; I've studied the arguments for and against the Iraq war and the Global War on Terror. My search has been for a bipartisan common denominator. There are more than this, but one common denominator is the relationship between conflict and democracy. Those of us who avoid conflict are inadvertantly avoiding democracy. Democracy demands conflict. Not resolutions, but conflict. Sustainable resolutions such as liberty and justice were conceived in the heat of conflict and were adopted later by victorious men and women. That's how society evolves and that's why ours is evolving so quickly.
Not all Americans realize their role in this particular conflict but many do. Many of those that do understand their role will never find the words to describe it. For those that do realize how important they are and the role they play in fulfilling their legacy, they will sustain our great nation for future generations. We cannot dismiss the fact that our children will undoubtedly be called upon to serve the cause of civilization. It will be up to them to fight the shadows of barbarism we leave behind when we're gone. Will they look back on our generation as one that added momentum to our timeless cause? I hope so.