The Barack Obama administration has just authorized another round of arms sales to Taiwan worth $1.8 billion, which Beijing has strongly opposed because it undermines the country's sovereignty and national integrity.
China has maintained this position since Beijing and Washington normalized their diplomatic relationship, and demanded that the US immediately stop selling arms to the island.
In fact, the US had promised to reduce the quantity and quality of arms sales to the island once the tensions across the Taiwan Straits eased, and eventually stop them. But 33 years after the US made the promise, in the form of the third China-US Communiqué in 1982, Washington has been continuing to sell weapons sales to Taiwan. It has been violating its promise despite the easing of tensions across the Straits, and the peaceful and massive two-way flow of people and goods.
The US may argue that the Chinese mainland's rise poses a greater "threat" to Taiwan, which warrants it to continue selling arms to the island. In the same vein, one could also argue that, as the world's sole superpower, the US automatically is the greatest threat to the world. But this logic is too simplistic.
The mainland's rise may have been dramatic, but it has not changed its intent of a peaceful reunification with Taiwan. The mainland has made it absolutely clear that it would adhere to a non-peaceful approach only in the event of Taiwan's de jure independence. Otherwise, Beijing remains committed to promoting peaceful interaction in partnership with the Chinese compatriots in Taiwan. The recent meeting between Xi Jinping and Ma Ying-jeou in Singapore is proof such efforts are based on the principle of one-China.
No matter in which way you look at the cross-Straits relations, they are China's internal affair, not part of international relations, and do not brook outside interference. Despite this, China has adopted a cooperative approach for decades in the hope of bringing about peaceful reunification.