How to use "defense" in a sentence

"'Laughter is a balm for the afflicted, the best defense against despair, the only medicine for melancholy.'"

"In case you didn't know it, since the Cold War ended and California took such a big hit in the defense downsizing, Nevada has more Pentagon-supported industries and installations than any state in the union

We don't have any choice but to maintain a strong defense

Then, even with Danny jamming the enemy's weapons, she and Elliot would be able to escape only if they slaughtered their way out, and she knew that neither of them had the stomach for that much murder, perhaps not even in self-defense.