This year’s US presidential campaign is speeding toward its climax. With US President Barack Obama’s and Republican rival Mitt Romney’s campaigns blasting at each other, US-China relations may become collateral damage.

The People’s Republic of China has long been a convenient political target. Despite the obvious benefits of a bilateral relationship which is both peaceful and profitable, US presidential candidates have for years sought to win political points by criticizing Beijing.

However, new administrations usually shift to a more pragmatic policy approach.

“Presidents tend to recognize that the Chinese don’t react well when you point a gun to their head,” Uri Dadush of the Carnegie Endowment said.

However, a willingness to work with Beijing inevitably triggers the cycle anew. As a US presidential candidate Obama termed then-US president George W. Bush “a patsy” in his dealings with China and promised to go “to the mat” with China over its trade practices. The Obama administration began by emphasizing economics and trade and US Secretary of the Treasury Timothy Geithner charged China with “manipulating” its currency.

However, the administration’s claims grew less shrill as Washington issued more debt. The Obama administration later even played down China’s human rights issues.

Controversies in the South China Sea led to greater discord, encouraging the administration to mount its so-called “pivot toward Asia.” China’s state-run media said that Secretary of State Hillary Rodham Clinton was “a person who deeply reinforces US-China mutual suspicion” and who “has brought new and extremely profound mutual distrust between the mainstream societies of the two countries.”

Washington and Beijing also disagreed over the best approach for Syria. Beijing rebuffed Washington’s attempts to place greater pressure on Damascus, leading Clinton to denounce Beijing’s actions as “just despicable.”

Nevertheless, the administration maintained a solid working relationship with China. On her way to China last month Clinton observed: “Even when we disagree — believe me we can talk very frankly now — we can explore the toughest issues without imperiling the whole relationship.”

By contrast, Romney began attacking China during the primaries (as did several other Republican candidates). He decried Beijing for engaging in “behavior that undermines international security” and promised to adopt policies to check its “harmful ambitions” and to encourage “the evolution of China toward a more politically open and democratic order.”

He criticized Clinton for relegating “the future of freedom to second or third place,” denounced the US president for being a “near supplicant to Beijing,” and claimed that the administration’s “weakness” had “only encouraged Chinese assertiveness.”

Romney targeted trade with China. He claimed that Beijing was a “cheater” and promised to label it a “currency manipulator” on day one in office. He also decried the US administration’s “trade surrender.”

Obama returned fire. He criticized Romney’s stewardship of Bain Capital, especially its investment in Chinese firms and outsourcing of jobs to China, and initiated two new WTO cases against Beijing.

Both sides are also featuring China in their campaign ads: “If you live in Ohio or Wisconsin and own a television, you might be under the impression that America’s main foreign enemies are the exporters of China,” Ramesh Ponnuru said on Bloomberg’s Web site.

In September, China retaliated by filing its second WTO case against the US within a month, contending that anti-dumping and countervailing duties imposed by the administration violated international trade rules. As for Romney, the China Daily wrote: “By any standard, the US Republican presidential candidate Mitt Romney’s China policy, as outlined on his official campaign Web site, is an outdated manifestation of a Cold War mentality.”

Worse could come. Bonnie Glaser of the Center for Strategic and International Studies warned of a potential shift in Chinese foreign policy.

“The US Asia pivot has triggered an outpouring of anti-American sentiment in China that will increase pressure on China’s incoming leadership to stand up to the United States. Nationalistic voices are calling for military countermeasures to the bolstering of America’s military posture in the region and the new US defense strategic guidelines,” she said.

Much is at stake as the two governments attempt to work through sometimes contentious differences. Even though the next administration is likely to adopt a policy of pragmatic engagement toward China, years of hostile rhetoric risk pushing policy in both nations to the extreme. That is in no one’s interest, including the US’ friends, such as Taiwan.

Washington and Beijing must peacefully accommodate each other’s sometimes conflicting interests. On her recent trip to China, Clinton summarized the challenge: “Our two nations are trying to do something that has never been done in history. Which is to write a new answer to the question of what happens when an established power and a rising power meet.”

For the sake of their respective peoples — and those who would be caught in the middle — that answer must be peaceful cooperation.