You don’t think those in the Pentagon would lose sleep if they thought our enemies had drones that could enter our airspace in ways that are basically undetectable and had been doing so for the last 16 years (not sure if the USS Nimitz phenomena were actually in our airspace, but they seem to have had that ability)?
They don’t worry about things until its a verified threat. They focus on the missions they are budgeted for. If you ever worked for DoD, you would know this. The real world is not the Hollywood world.