You're missing the very important concept of soft power. We don't need to defeat our enemies using superior proprietary knowledge. Instead we export our cultural memes to them until they're no longer motivated to be enemies. We get far more influence and respect as the destination for international students the world over, than we do as the owner of an aircraft carrier.

They have to put up walls to keep Americanism out and their own citizens in. NATO was about piercing the Iron Curtain, not building our own parallel to it.