With the risk of being political, I see nothing "defensive" or moral about the military, even in the most advanced nations that are supposedly paragons of human rights.
Take the "dictator attacks weaker country" narrative. The NATO defensive alliance fits this narrative by providing weapons and military training to weaker Ukraine so it can defend itself against the aggression of bigger Russia. On the other hand, the same defensive alliance has no scruples to providing weapons to Israel so it can wipe out and cause immense suffering and casualties to Palestine, a weaker nation.
Which brings me to my conclusion that there is nothing inherently moral about the army, it's just a blunt instrument to do the government's bidding. Hence, I don't see military as our "protectors", but as the government's institutionalized thugs. I also don't see a reason for them to be lauded for their actions, as their actions are often immoral and sinister. I am talking things like the military secrets Assange unveiled, or the illegal treatment of prisoners in Guantanamo, or the sometimes indiscriminate bombings of civilians to hit 1 potential target.
And since they are not protecting me but the government's interests, I don't see a need to thank them for their service more than I see the need to thank bouncers at a disco I don't own for theirs.