The Taiwan issue, which was a source of repeated tension between Washington and Beijing for decades, has been mercifully quiet for the past five years. Ma Ying-Jeou’s election as Taiwan’s president in 2008 marked the onset of a decidedly more conciliatory approach toward the mainland than the policies his immediate predecessors pursued, and U.S. leaders were relieved to put the contentious matter of the island’s status on the diplomatic back burner. But, as I discuss in a new article in China-U.S. Focus, there are now signs that the period of quiescence may be coming to an end.

Because of domestic political reasons, as well as growing unease about Beijing’s intentions, Ma’s government is pressing the United States to sell an assortment of modern weaponry, including advanced versions of the F-16 fighter. The Obama administration is also under mounting pressure from Taiwan’s friends in Congress to take that step and increase military support for Taipei in other respects. House members inserted an amendment in the 2013 National Defense Authorization Act urging President Obama to sell Taipei the F-16 models Ma’s government sought. Reports also circulated in Taiwan that a senior Republican, Senator James Inhofe of Oklahoma, assured Taiwanese officials during a visit to the island earlier this year that the United States would approve the sale of Apache attack helicopters in 2014 and Patriot missiles in 2015.

However, arms sales of any sort to Taipei have long been a major irritant in U.S.-China relations. Chinese leaders have never wavered in their contention that Taiwan is rightfully a part of China, and they view U.S. weapons sales as provocative. Beijing is especially wrathful about transfers of modern weapons with offensive potential. Selling the advanced F-16 models, the Apaches, or the Patriots would likely produce a surge in bilateral tensions. Washington and Beijing are already on poor terms regarding other issues, especially the Obama administration’s unsubtle support for East Asian countries challenging China’s territorial claims in both the South China Sea and the East China Sea.

U.S. officials need to proceed with considerable caution on the issue of arms sales. Understandably, Washington would like to see Taiwan maintain its de facto independence and remain out of Beijing’s political orbit. But a cordial relationship with China is important to America, both strategically and economically. The last thing this country needs is a renewed crisis in East Asia.