In 1962, Chinese President Liu Shaoqi warned Mao Zedong: “History will record the role you and I played in the starvation of so many people, and the cannibalization will also be memorialized!” Their exchange is in “Tombstone,” a 1,200-page history by Yang Jisheng, who documented 36 million deaths under Mao’s agrarian reforms. Yet Liu’s tacit prediction of harm to Mao’s reputation from the horrific revelations was unfounded — at least in China. Mao appears on more Chinese currency than George Washington does greenbacks, his 57,000-square-meter mausoleum sits in the heart of Beijing, and his worldview has been embraced unapologetically by current President Xi Jinping. Yang’s book and other accounts of the famine are banned in China. History is recorded, but it is kept out of reach of most Chinese.

This week marks Book Expo America (BEA), the publishing industry’s annual trade show. BEA usually places a foreign country in the spotlight; this year it’s China. A 500-strong Chinese delegation is coming to showcase literary talent and tighten ties between the world’s two largest book markets. But as they wine and dine Chinese literary luminaries, Americans must not forget that literature is among China’s most controlled state industries, used to propound government mandates and suppress ideological heresies. As leaders of an industry predicated on robust protections for free expression, U.S. publishers need to make sure that in selling in and out of China they aren’t also selling their souls.

China is tantalizing for an American industry facing shuttering bookstores and pinched pricing models. China’s fast-growing retail book sales exceeded $8 billion in 2013. The country is producing terrific writers with global audiences across diverse genres, including literary fiction, children’s books and business titles. China buys rights to more than 16,000 foreign titles annually.

But China’s outwardly vibrant literary culture masks a harsh reality. In the Chinese government’s battle to control information, publishing is a heavily fortified line of defense. China has 580 official state-controlled publishers and no fully independent ones. Regulators license publishers, censor books and close defiant houses. References to the Tiananmen Square massacre are expunged to the point that many Chinese born after those killings do not even know they happened. Books that criticize the government or speak about persecution of minorities such as Tibetans and Uighurs are also banned. Chinese editors enforce the rules vigilantly. If they let an offending passage through, they can be put out of business. As revealed in a new PEN report, foreign authors are routinely censored without their authorization: Paul Auster, Andrew Solomon and Hillary Clinton learned only after the fact that Chinese versions of their books were doctored. In coming in force to BEA, the Chinese government aims to rebuke the notion that creative freedom is essential to flourishing cultures. It hopes to disarm critics by demonstrating that its repressive one-party system can foster top-tier literature. It asks the world not to think or speak of those Chinese writers who, left off the official delegation, are intimidated, silenced or jailed for life because of their writings.

In readying BEA, neither the Chinese nor their American hosts took much trouble to mask the message. In promotional copy only a Chinese apparatchik could love, the BEA program promises attention to a book offering “a panoramic view of the crimes committed to the Chinese people by the Japanese militarists” and materials “for educating in patriotism and safeguarding national interests.” There will be a book launch for “The China Dream” by Liu Mingfu, a hawkish military analyst known for advancing theories of Chinese exceptionalism and supremacy; the description of the session leaves out the book’s subtitle, “Great Power Thinking and Strategic Posture in the Post-American Era,” while promising to “invite Chinese and American celebrities” to “create favorable public opinion about the book and shape its influence.”

For American publishers, defending free expression has been a core value that has also made good business sense. Publishers have fought book bans, defended libraries against government snooping and donated generously to free-expression causes. As China’s influence widens, U.S. publishers face choices between principles and profits. Hollywood studios now invite government censors onto film sets such as “Iron Man 3” so that movies pass muster in China; American writers and editors self-censoring in the original English to anticipate Chinese government mores may not be far behind. Venerable U.S. publishers at the forefront of engaging China should commit to a publisher’s Hippocratic Oath aimed to ensure that, at the least, their involvement in China does not further harm free expression.

Publishers should publish and publicize more books like “Tombstone” that Chinese publishers must shun. Publishers should ensure that when Western books are put into Chinese for publication on the mainland, translations are properly vetted so that authors can review excisions, protest them and make informed decisions about whether cuts distort their ideas and arguments. Deletions should be noted in the Chinese versions, with the missing material made available online. Publishers also need to engage credible China experts to help discern the agendas of proposed partners and boundaries between literature and propaganda. Unless U.S. publishers go in with eyes open, this year’s book expo could leave them badly exposed.