Ah, our poor, lost younger generation who know not what they defend. You think too highly of yourselves if you think you are being called upon to defend king and country. 'Tis no ideal, no ideology, no Grand Plan you bear arms for. All the older generation asks is that you see fit to defend yourselves and your home, that's it.
What home, you ask? Remember the people who call you family, those you call your friends? That home. Like family, you don't get to choose whom you live with, though you can choose whom to be friends with. So it's not the place, but the people you share meals with from time to time whom you are defending. It so happens they all have to live somewhere, so yeah, that home.
If you don't know what you're defending, then you perhaps don't think your family and your BFFs are worth defending. You don't think of yourself as worth defending. That's fine. Lots of young people feel the same way. There were the Roman punks chillaxin' in their bounty. Tactically and technologically they had the best army in the world defending them, but the barbarians dropped by and trashed the place anyway, raping, pillaging and slaughtering as they went. What we DO remember of the Romans are the remains of what their forefathers had built... that's about it. Good company, you youngsters keep.
There's only one problem I have with you not knowing what home you're defending. You are talking about MY home too. Could you do an old guy a favour and wait until I no longer have a need for a home on Earth before you toss it away to the barbarians? Yes, the ones who are eyeing all the nice things you kids have 'cos the only way they can see themselves having the same privileges as you is by prying them from your cold, dead fingers. The same ones you are calling out to like a wounded duck calls out to hungry wolves for a swift and merciful end; the ones you are inadvertently inviting home with your legs wide open.