Much of the media buzz surrounding Chinese leader Xi Jinping's regal visit to the United States centered around a limited agreement to prevent cyber hacking. Although that pact is needed, perhaps more attention in U.S.-China relations should be given to dangerous flashpoints in the South and East China Seas. In these places, the two nuclear-armed powers could be dragged into a conflict that could escalate perilously.

In both seas, China is engaged in territorial disputes with other countries in the region. Because of President Barack Obama's "pivot to Asia," the United States has been strengthening its Cold War-era alliances with some of these nations to contain the rising China. Because the Cold War is so yesterday, the U.S. government no longer calls its policy of encirclement "containment," but that's still what it is. Major U.S. formal allies in the area of these seas include Japan, South Korea, the Philippines, and Australia, and a major informal ally is Taiwan. Also, the United States, with China in mind, has improved relations with other non-allied nations in the region that are uneasy about China, such as the former U.S. enemy and still communist Vietnam.

As part of the "pivot," the United States has transferred more of its military forces to the East Asian region. And there is talk of reestablishing a U.S. military presence at Subic Bay naval base in the Philippines, from which Filipinos expelled the United States in 1992. Even worse, Admiral Harry B. Harris, Jr., the top U.S. commander in the Pacific, has said the U.S. plans to get more directly involved by increasing U.S. naval patrols in the South China Sea.