Just when it appeared that long-standing squabbles between Beijing and Washington over such issues as trade imbalances, the valuation of China’s currency, and sanctions against Iran might be fading, a new set of disagreements is now exacerbating tensions. Two issues in recent weeks are producing a marked chill: how to deal with North Korea, and how to resolve rival territorial claims in the South China Sea between China and several of its Southeast Asian neighbors.

The spat regarding policy toward North Korea erupted in the aftermath of the sinking of the South Korean naval vessel Cheonan. When Seoul mounted an investigation that concluded the ship had been sunk by a North Korean torpedo, the United States strongly backed its ally. Washington vehemently condemned Pyongyang for an act of aggression and joined Seoul in pressing for a punitive resolution from the United Nations Security Council.

China’s response was quite different. Chinese officials argued — and continue to argue — that North Korea’s guilt was not established. They called for a new investigation with more international (presumably including Chinese and Russian) participation.

Obama administration officials were disappointed at China’s position. They believed that Pyongyang’s guilt was clear, and they warned that North Korea’s reckless conduct was dangerously de-stabilizing. U.S. policymakers had quietly expressed frustration for years about Beijing’s reluctance to pressure its ally to make concessions regarding its provocative nuclear program. But China’s failure to condemn Pyongyang’s rogue behavior in the Cheonan episode was seen as irresponsible.

Nevertheless, the Chinese government did not waver in its support of North Korea. Indeed, Beijing insisted that the UN Security Council resolution condemning the Cheonan sinking not name that country as the perpetrator. Washington agreed to such anemic language rather than trigger a Chinese veto, but U.S. officials were not happy, and they publicly criticized China’s stance.

The next development saw Washington’s conduct irritating Beijing. In late July, the United States and South Korean naval and air units conducted joint military exercises. The motive was clear. As Secretary of Defense Robert Gates acknowledged, those exercises were meant to “send a strong message” to Pyongyang that further military provocations would not be tolerated.

This time, it was Beijing that responded angrily, accusing Washington of needlessly escalating tensions in the region. The U.S. decision to include an aircraft carrier in the exercise was considered especially provocative, and some Chinese suspected that the Obama administration was sending a “strong message” about American power to China as well as North Korea.

While the quarrels regarding Korea were going on, tensions on the second issue — the South China Sea — erupted. At an ASEAN Regional Forum meeting in Hanoi, Secretary of State Hillary Clinton stressed that the United States “has a national interest in freedom of navigation, open access to Asia’s maritime commons, and respect for international law in the South China Sea.” She went on to advocate a binding code of conduct for the various nations, including China, that are claiming disputed islands in that body of water. Clinton also proposed the development of an institutional process for resolving those disputes, and indicated that the United States was willing to participate in that process.

Beijing’s reaction was swift and caustic. Foreign minister Yang Jiechi portrayed Clinton’s remarks as “an attack” on China. Questioning Washington’s sincerity on the issue, he stated that “nobody believes there’s anything threatening the region’s peace and stability.” Finally, Chinese leaders made it very clear that the United States had no legitimate role to play in resolving competing territorial claims, and that any attempt to do so would be decidedly unwelcome.

The diplomatic barbs being exchanged between Washington and Beijing reflect much more than disagreements about specific issues — although that aspect certainly plays a role. In a larger sense, we are witnessing a phenomenon that the world has seen numerous times before. It is the inherent tension that develops between an incumbent hegemonic power and a rising great power that is beginning to challenge that hegemon.

No doubt Washington is annoyed at Beijing for its stance regarding North Korea and China’s breathtakingly broad territorial claims in the South China Sea. (Indeed, China regards virtually that entire sea as its territorial waters — something that, if enforced, would have profound implications for international navigation and commerce.)

But U.S. leaders also see such behavior as a manifestation of China’s attempt to establish itself as the leading country in East Asia, gradually displacing U.S. power and influence. Already, American hawks are warning about that challenge and urging the Obama administration to take countermeasures. Writing in the pages of the Wall Street Journal, neoconservative scholar Daniel Blumenthal praised Clinton for standing up “to China’s bullying.” He went on to propose that the United States orchestrate a thinly disguised diplomatic and military containment policy against Beijing.

It is always a delicate moment in international affairs when a rising power begins to erode the dominance of a hegemon. All too often, that process turns out badly — sometimes disastrously so, as with Imperial Germany’s interaction with Britain in the early 1900s and Japan’s relations with the United States in the 1930s and early 1940s.

Fortunately, there are a few counter examples of a peaceful transition to a new, more equal relationship. The most prominent case was Britain’s willingness to concede preeminence in the Western Hemisphere to the United States in the 1890s. That concession, as painful as it might have been to London at the time, paved the way for cooperative ties for the next century and beyond.

For a variety of reasons, not the least of which are the stark differences in political systems, it would be far more difficult for the United States to accept China’s preeminence in East Asia. But the mounting tensions emphasize that U.S. policymakers need to develop a more coherent strategy. Drifting from confrontation to confrontation with a rising China, as Washington is now doing, will certainly lead to a bad outcome.