The truth is you don't know what the national security state is costing us. It's too secret to disclose.
But the broad strokes are that it has direct budged and non-budgeted costs in the range of $1T a year. On top of those expenditures are the revenues that are generated by selling weapons systems overseas. In some years that's tens of billions more. That's on an economy of ~$15 trillion. So that's on the order of 6.5% of the entire economy is directly involved in this sector.
That is not small. It is not tiny. There are few sectors that are as big and probably none that are bigger. The entire auto sector - manufacturing, sales, advertising, exports, imports, repair shops, parts shops, the whole supply line, shipping, trucking, etc is 5-6%. The entire healthcare sector including every doctor, every nurse, every insurance agency, R&D, the drug industry, every drug store, all the drugs, the pharmacy items in the drug store, that entire supply chain, heavy medical equipment, home health care, hospice, hospitals, hospital construction, medical tourism, advertising, medical lawsuits, lab services, medical schools and everything else lightly related to the medical business is about 11% of GDP.
Put it this way. If the national security industry was it's own country, based on GDP, it would be the 15th biggest in the world. Bigger than all of the entire South Korean economy, put together.