(Newser) – Chinese warships weren't just exploring international waters when they ventured close to Alaska on Tuesday. The five ships came within 12 nautical miles of the coast, the Pentagon says, meaning they penetrated US territorial waters, reports the Wall Street Journal. China says its ships sailed to the Bering Sea in a "routine arrangement ... not aimed at any particular country and target" after participating in joint exercises with Russia. The Pentagon says the ships kept to international law as per the principle of "innocent passage." But the venture is interesting because Beijing opposes any US Navy presence in Chinese waters or the international waters just beyond.

"These operations are a big step forward for US interests in that Beijing now has no basis to object to similar passage through China's territorial sea by the US, for instance in vicinity of China's islands in the South China Sea," says an expert at the US Naval War College. He adds China's operations near Alaska "are also a big step forward in that China's blue-water navy has announced its arrival as a global force." Indeed, before 2006, China's ships rarely left their own shores. They've since been used off Libya and Indonesia and in exercises in Hawaii. Officials tell Reuters that the Pentagon is continuing to monitor the Chinese ships, which as of yesterday were on their way home. (Read more Chinese navy stories.)

