There are a lot of differences between the two countries. The main source of these differences is that the US is the status quo power, while China is, to some extent, a challenger to the status quo. The US has no experience in dealing with an upcoming power peacefully. Notably, because of China's ideological background, the US is especially concerned with China's rise. The debate on "engagement" or "containment" toward China in the US reflects this fact. The US government has defined a "comprehensive engagement" strategy toward China. It seems that this policy may not be shifted to a different direction in the near future though due to its domestic politics, the debate on US policy toward China will repeatedly arise. The US will surely continue to keep an eye on China's rise and take some pre-cautious measures defending China's challenge. But it should not be in the US' interest to take China as its main opponent. The "constructive strategic partnership" simply affirms this picture. In US foreign policy thinking, though China may not be a friend or an ally, it is a power to be befriended and cooperated with. China does not intend to challenge the US' dominant position, nor does it have the need to go against the US by allying with other powers.
China's relations with other powers have been greatly improved. It has established "cooperative partnerships" with several European countries, Russia, and Japan. These partnerships have different emphasis, degree, field, and means of cooperation, yet they all contribute to institutionalize a framework for dialogue, and collaboration. The strategic partnership for consultation between China and Russia has not just significantly stabilized their relationship, but also helped solve many disputes which existed before. China and Japan have agreed on a partnership for peace and development, though due to their historical grievance and especially strategic disarray, they still seem to be "distant neighbors." A stable and cooperative relationship is not just beneficial to the two, but it is also very important for the region. It is not easy, however, for the two countries to find a common ground to build deep trust and cooperate in the security field under the re-strengthened US-Japan military alliance.
The most troublesome issue is how to keep cross-straits relations smooth. There are two potentially serious dangers: either from pro-independence in Taiwan gathering steam, and thus provoking a crisis; or, the Mainland side growing impatient, and leading to a conflict. Peaceful reunification and stability in the Taiwan Strait area is one of the most important parts of China's overall security. It could fundamentally change China's foreign policy and lead to conflicts with others if it is not handled properly both by China itself and other related parties. While the Taiwan issue itself is an internal affair of China, we must recognize that there are factors that "internationalize" it. On the one hand, many countries have extensive economic and political ties with Taiwan, and therefore, they have a direct interest. On the other hand, it is understood that cross-straits relations are connected to many countries' interests. Especially if tension broke out, it could endanger countries with a direct interest in this region. The Taiwanese authority will certainly take advantage of these factors to expand its "living space," and at the same time, other countries may use Taiwan as a bargaining chip against a rising China. All these have greatly complicated the Taiwan issue and restrained China's policy choices. China will not ignore the Taiwanese authority's reckless behavior, nor can it see no response to other countries' support or even encouragement for Taiwanese independence.
