Common Defense is mentioned in the Pre-Amble to the U.S.C., which needs no interpretation. This was based off of what the Founders has seen in Great Brittan; as well as what Brittan had set up in America. The Founders were suspicious; for good reasons.
Standing armies have been utilized by Monarchies to oppress the people. This was also fore-warned of in 1Sam.8:5-20 from our Creator speaking through His Prophet Samuel. Our Lord stated that choosing your own king was a rejection of Him. Samuel also advised them that this was a wicked request.
Common Defense is the purpose of a standing military: this is Homeland-Security. Minus our Lord, the leaders become Caesars and make everything about themselves. To support the Beast, people, and private property is taken. There is excessive taxes. The military is employed for advancing the Empire.
Private-currency-producer, and it's Collection's-agency has turned Nations into Host, for Parasites: and the Standing military into their strong-arm. Control and destroy is their Doctrine. Common Defense is not operating 150 plus military bases around the world. These are pay-offs.
There is a Caterpillar-Wasp that injects it's eggs into a caterpillar. The Wasp develop and eventually eats its way out. The injured Caterpillar eventually dies - of starvation, after not eating and protecting the babies. This is what has happen to leaders around the world: they are dying as Host.
This not Common Defense!