Slightly more than 30 years ago, millions of Americans watched helplessly as pro-democracy protests in China were crushed ruthlessly. Our horror at the Tiananmen Square massacre was mixed with admiration for the courage shown by more than a million Chinese in standing up to their government.

Now, something similar may be happening in Hong Kong. There, months of protests against Chinese rule appear to be building to a crescendo.

Hong Kong was ruled for many years by the British. Now, however, it is referred to as an “autonomous” region of China, being transitioned to full control by Beijing. Once free and prosperous, Hong Kong’s 7.4 million people are beginning to feel the weight of totalitarianism. They feel their liberty and financial well-being ebbing away.

Some have begun protesting against that, in well-publicized confrontations with Chinese authorities. To date, violence has been relatively rare, though some has occurred.

That may be changing. Beijing’s ruling class is not accustomed to having its authority challenged. It is habituated to coming down hard on dissent.

But what can Americans do to help the protesters in Hong Kong? Virtually nothing, as was the case in Tiananmen Square. Neither the United States nor any other country has the ability to rescue the protesters. Even an attempt to do so could set up a wider conflict with China.

Some of the protesters in Hong Kong seem determined to fight for their liberties. God bless them. Sadly, they are on their own.