By Sun Xihui As in other aspects, the government of US President Donald Trump has marked a major shift in its position regarding Taiwan. From Trump taking a phone call with Taiwanese leader Tsai Ing-wen and questioning the "One China" policy to later refusing to meet Tsai when she made transit stops in the US or have another phone call with her and promising to stick to the "One China" policy, Trump's stance toward Taiwan has changed fundamentally. Given the rules of international relations, such changes have their own internal logic. A country's foreign policy is determined by its objective national interests while still being influenced by the subjective motives of its leader. National interests are decided by a country's strength and an international structure comprised of countries with different strengths. Taiwan is a part of China rather than an independent country. But as an economic and political entity, Taiwan has a unique position in China-US relations. The Chinese mainland, Taiwan and the US interact with each other as three parties and US-Taiwan relations maintain a special "bilateral" feature subject to Sino-US relations. The law of international relations can explain the changes of US policies toward Taiwan. International actors and the international pattern jointly form the international system structure. The international pattern reflects the different strengths of countries. In the current international order, there is one super power and a number of major powers. But a "two superpowers, many major powers" order is increasingly taking shape in the Asia-Pacific region. This means that China is gaining similar strength and influence to the US in the Asia-Pacific region, which serves as an important indicator for regional players to define their own interests. From a national level, a country maximizes its own interests with its strength as the basis and seeks corresponding foreign policies. The past disparity in strength between China and the US in the Asia-Pacific region has been bridged due to China's rise in its own strength and international status, resulting in structural conflicts and a strategic rivalry between the two. Washington views Beijing's rise as a challenge to its regional hegemony. Therefore, it tries all measures to contain China's rise, including playing the "Taiwan card." On the other hand, the balance of power between China and the US guarantees stability of this bilateral relationship, encouraging both nations to maintain cooperation and avoid confrontation. The US' Taiwan policy also abides by this principle. From an individual level, the preferences of leaders also affect international diplomacy. Trump is a successful businessman but has no political experience. His unique characteristics make him tend to apply his business experiences to political governance. Trump attaches importance to practical interests rather than ideology and values. This means the Trump government will not support Taiwan out of ideological or value motives as previous US governments have. Instead, it will deal with China-US relations and craft Taiwan policies based on US interests. In Trump's eyes, foreign policies can be traded. But for China, the Taiwan question and the "One China" policy cannot be negotiated, which means Trump's "trade" will not work. This explains why there has been a notable reversal in the Trump government's attitude toward Taiwan. Structural changes in Sino-US relations require the US to deal with this bilateral relationship and the Taiwan question prudently, and the Trump government has realized this. A rational US government will base its Taiwan policy on the country's best interests. Taiwanese politicians hoping to confront the mainland by siding with the US are just absurd and unrealistic. (The author is an associate professor with the National Institute of International Strategy at the Chinese Academy of Social Sciences. [email protected] Follow us on Twitter @GTopinion) (Global Times)