I believe that a strong defense keeps the peace. This is what I was taught while I was in the military.
There is a United Nations Charter or something like that, that makes it unlawful for any nation to declare war with another nation.
Before the world wars, the law of the land was to declare war on them before they declare war on you. After the world wars the law of the land was revised to make such an act unlawful. Now, you cannot start a war with another country unless you are first attacked and if you have a strong defense, no country in their right mind would attack you. This is how a strong defense keeps the peace, and thus was the law.
Unfortunately we have gone backwards and broken the law and because war crimes are not being enforced, the new law is now the old law, attack them before they attack you.
Iraq never attacked us and our forgotten mission in Afghanistan was to capture and or kill Al-Qaeda and go home, so our war in Afghanistan is over, what are we doing over there?
Because of what we are doing and have done has been unlawful, even against our own constitution, if someone was to join the military today, I would have to discourage them