The United States is again considering selling weapons to Taiwan, which has caused quite a stir in China. At present, the Chinese mainland and Taiwan are enjoying increasingly close economic and trade relations, with frequent dialogue and exchange visits. In such a context, the U.S. arms sale to Taiwan will be a gross interference in China's internal affairs and a grave threat to China's security and core interests.

The majority of the people on both sides of the Taiwan Strait hope for cooperation and common development. If the United States continues to sell weapons to Taiwan against Chinese people's will, its hypocrisy in important matters concerning China's core interests will be further exposed to the daylight.

The dual nature of the U.S. policy toward China comes from two conflicting attitudes of U.S. politicians toward China. Some U.S. politicians see China as a strategic rival, and thus advocate containing China through various means, including playing up the "China threat theory," selling weapons to Taiwan, supporting anti-China separatist forces, and undermining China's cooperative relations with other countries.

At the same time, some politicians in the United States see China as a partner, and advocate cooperating with China and accepting the peaceful rise of the country. They have called on both countries to work together to resolve conflict and enhance mutually beneficial cooperation.

The two conflicting attitudes have resulted in the alternation of "China threat theory" and "China responsibility theory," and frequent switches between hawkish and dovish U.S. foreign policy toward China.

The United States has been strictly observing diplomatic protocol, and appears to have sincerity to improve its relations with China. However, when it comes to China's strategic interests, the United States will become fully alert and sometimes may take irresponsible actions at the expense of stable relations with China.

Certainly, the "dual nature" has also showed in a way the importance and complexity of China-U.S. relations. However, the double-faced hoaxes played by the United States have often led to the fluctuations in China-U.S. relations and inevitably caused people to doubt the essence of its diplomatic policy.

The inappropriate "dual nature" is just a major characteristic of the U.S. foreign policy. The United States adopted different attitudes amid the unrest in East Asia and North Africa in early 2011. The United States actively supported the protests within anti-American countries such as Iran on the one hand and remained silent when facing the protests within its allies on the other hand.

The New York Times newspaper bluntly pointed out that the United States has applied a double standard because it has strategic interests at play. Similarly, the United States has always adopted two opposite attitudes toward other countries and itself in terms of online freedom. Internationally, the United States has required other countries to ensure unlimited "Internet freedom" and used it as a major approach to impose diplomatic pressure on other countries and seek hegemony. Domestically, the United States has imposed strict restrictions on the Internet under the cover of the fight against terrorism. The United States has also applied this type of double standard in terms of human rights. Despite high domestic crime rate and crowded prisons, the United States enjoys acting as the world's human rights judge.

The root cause behind the double-faced U.S. foreign policy also lies in that the United States still regards itself as the world's hegemonic player. Driven by that mindset, the United States tends to adopt the tactics of "utilization" and "containment" to deal with the emerging countries.

The United States needs China to share responsibilities and cope with crises on the one side and is afraid of the challenges from China on the other hand, so that it has often been inconsistent and even made the moves such as weapon sales to Taiwan that seriously jeopardize China's core interests. The white paper on China's peaceful development recently released by the Chinese government has showed that the worries of the United States about China are simply unnecessary.

It is perhaps more helpful for the United States to take time to reflect on the dual nature of its diplomatic policy.