Not another Tiananmen

China may be lining up tanks in Shenzen in a show of military force against the instability in Hong Kong. The sporadic protests in the city of 7.5 million that began in June with 2 million participants, led to protesters descending on the city’s international airport, an important global hub. News footage showed some armed forces across the border from Hong Kong. The sight is a scary reminder of the 1989 Tiananmen Square massacre that occurred during a democracy movement in Beijing.

The protests and unrest were triggered by an extradition act pursued by the semiautonomous government in March. Hong Kong citizens feared the law could be abused by Beijing to demand the handover of anti-China activists and other Chinese residing in Hong Kong. Although Hong Kong authorities announced that they would suspend the act in June, citizens did not back down and demanded the resignation of Chief Executive Carrie Lam and a direct election to pick their own head of the city. Beijing does not like such a challenge to its communist regime and has upped its propaganda campaign suggesting that the U.S. is behind the unrest. Military officials began calling the protesters “terrorism” forces.

The crisis gives Chinese President Xi Jinping his biggest political test as this year marks the 30th anniversary of the Tiananmen Square demonstrations and the 70th year since the founding of the People’s Republic of China. Under local laws, Hong Kong authorities can ask the Chinese government to intervene and send forces to restore order.

The buildup of unrest in this important financial hub for Asia may not stop anytime soon. The global economy will suffer further on top of the woes from the extended trade war between the U.S. and China. That could be harder for Korea, which is involved in its own diplomatic and trade spat with Japan. Beijing must avoid using force in Hong Kong, the symbol of open and free trade championed by China.

State media claim that China is not the weak state it was when it lost Hong Kong to western powers during the Opium Wars in 1842. When London returned the colony to Beijing in 1997, Chinese leader Deng Xiaoping vowed to keep capitalist and democratic systems intact in the city. Beijing must live up to that promise. It cannot repeat the tragic mistake of 30 years ago.