Cities spend years and millions of dollars preparing to host the Olympic Games - erecting stadiums and rebuilding acres of urban area. For the 2008 Games, China has made eye-popping investments in building venues to fulfill pledges made to the International Olympic Committee. But while the government comes through with infrastructure, it balks at honoring its pledges to improve the human rights climate before the Games, including explicit assurances to uphold press freedom. Now, only four months until the opening ceremony, Chinese leaders must be held to their word.

China's constitution and its signing of international treaties obligate it to uphold human rights. But China remains a one-party state without free elections, lacks an independent judiciary, censors the media and the Internet, bans independent trade unions and has lately repressed protests in Tibet. Human Rights Watch has extensively documented that the Games are in fact making the situation for human rights worse. As courageous government critics are jailed, as Tibet is sealed from reporters and any independent investigation, the most important question is: When, if ever, will the IOC speak out?

As Olympic chief Jacques Rogge put it when China was chosen as host, "The staging of the Beijing Games will do a lot for human rights and social relations." Make that "could do" a lot for human rights - but only if the IOC and world leaders are willing to press for discernable change. As Olympic corporate sponsors - including Coke, Visa and GE - use the Beijing Games to access the world's largest consumer market, they need to find a public voice and acknowledge that all is not well on China's human rights front. These companies are literally paying for the Olympics and their reputations are inextricably tied to the Games.

There are many individuals and groups inside China working constructively for progress ahead of the Olympics. They deserve support. Sponsors can and should insist on key reforms, including genuine access for foreign and Chinese media and a lifting of the curtain of repression in Tibet. China should put the same energy into human-rights improvements as it does into Games preparations.

Minky Worden is Media Director at Human Rights Watch.