That both the world and mainland China benefit from an autonomous Hong Kong was on display once again Tuesday when Twitter announced it has set up its Chinese headquarters in the former British colony. It shows a congressional push linking U.S. privileges to the continuation of such self-rule is timely.

The media giant’s move will allow it to sell its advertising services to companies in the People’s Republic of China, where Twitter has been blocked pretty much since it took off in 2009. The communist apparatchiks who still call the political shots in China fear free information and insist on maintaining a monopoly on it, but its companies need to communicate with the outside world and certainly will find Twitter of use.

Twitter made about a half-billion dollars in just the last quarter from advertisers who inject their “promoted tweets” into users’ timelines, according to Fortune Magazine.

Enter Hong Kong, a free-market paradise which Britain handed over to the PRC in 1997 after Beijing promised it would respect the city’s high degree of autonomy. Things have not quite turned out that way, as the Chinese Communist Party continues to renege on these promises and refuses to allow Hongkongers to vote freely for their chief executive.

There have been ham-fisted attempts to silence independent newspapers. But Hong Kong still retains enough freedom of speech that Twitter can serve the huge mainland market from the city.

“This is the first market we’ve gone into where we’re targeting outside of the country,” Twitter’s sales director for emerging markets told Hong Kong’s South China Morning Post.

The House bill attempts to put pressure on the PRC to respect its promises to Hongkongers, Britain and the world. It requires the secretary of state to certify to the president annually that Hong Kong is sufficiently autonomous before the United States can enact any law that treats Hong Kong differently from the PRC.

The city currently makes millions from such privileges; Hong Kong is, for example, exempt from technology transfer limits that apply to China.

The bill is bipartisan, sponsored by Republicans Chris Smith and Dana Rohrabacher and Democrats Eliot Engel and Daniel Lipinski. It is far from perfect, but it is a step in the right direction because it attempts to re-introduce U.S. leadership on the issue. Protests exploded in Hong Kong last year as thousands of demonstrators demanded their rights.

We generally tend to agree with the late conservative icon Stan Evans that bipartisanship is often “when Congress does something both evil and stupid.” But this bill is the exception that proves the rule.