Your circle that covers the entire continental US is a burst altitude of 300 miles
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Iran’s ship-launched missile test - reached an altitude of 700 miles where it was detonated. Roughly the distance from a launch point 200 miles off Altantic coast to the detonation point over Chicago.
That’s a DISTANCE of 700 miles, an altitude of 700 miles puts you in the exosphere twice as far from the earth as the international space station. And 700 miles distance only gets you from Chicago to a bit past Philly, not 200 miles into the Atlantic.