Communist China's sub circled Guam first

The Chinese sub that entered Japanese territorial waters three weeks ago, first circled Guam, according to the Japanese press. Surely they are testing our defenses and reactions, and those of the Japanese as well. From the end of the article:

China is believed to have learned a hard lesson when its military activities were contained by U.S. aircraft carriers during a period of cross-strait tension in 1995-1996. Chinese military authorities realized the need for quick deployment of submarines east of Taiwan. China has since conducted submarine drills and collected navigational data in areas between the so-called first line, which connects the Japanese archipelago and Taiwan via the Nansei Islands, and the second line, connecting the Ogasawara (Bonin) and Mariana islands.

If you've ever asked a US submariner how he refers to his sub, he'll say "boat." If you ask him, "well then, how do you refer to surface ships?" He'll say, "Targets." It is extremely difficult for surface ships to hide from "boats." Perhaps the Chinese wish to make our carriers vulnerable.