Yes but that US planes being tested over US soil. Later on they were used to spy on USSR. But why would Russia or any other country spy on the us coast and let

Yes but that US planes being tested over US soil. Later on they were used to spy on USSR. But why would Russia or any other country spy on the us coast and let US detect them. The only explanation that to me is probable is those are US UFOs being tested/interacted on with unaware normal troops. But then again, why? Why test them out near and airforce/navy exercises?