US sailing into uncharted waters

Suppose a country sends its warships with guided missiles regularly to the waters off Hawaii, conducts navy drills in the Gulf of Mexico or the Caribbean Sea targeting "hostile" forces, and test-fires conventional medium-range missiles in the Atlantic or Pacific Ocean near the US coast within just a few months, what would be the United States' response?

This is a no-brainer for anyone with even the basic knowledge of geopolitics.

But the US has been conducting such provocative operations in and around the waters of China, which it now considers a strategic competitor.