U.S. territorial waters is a belt of coastal waters extending at most twelve nautical miles (about 13.8 miles) from the mean low-water mark of any coastal state. The territorial sea is regarded as the sovereign territory of the United States, although foreign ships (both military and civilian) are allowed innocent passage through it. Imagine the physical penetration of the Pentagon or Fort Knox by way of our territorial boundaries. Imagine a virtual incursion of the seaport at Baltimore that included full access to the harbor of a foreign submarine.”]
Source: https://www.csoonline.com/article/2136383/violation-of-national-sovereignty.html