Of course you worry.It’s like you hold your breath until they are home.
Seriously, I worried about him when he was home, too. He's a risk taker, and I really prefer that he be taking risks under the knowledgeable supervision of a platoon sergeant than with three buddies, a fast car, and a six-pack. Even with jihadis on the loose, he's probably statistically safer there.
But I still worry anyhow. Worrying is in my genes, I got it from my maternal grandmother. :-D