The US government's goal is to protect the country and American people from terrorist attack. But the Chinese government's goal is to protect the communist party, to ensure it rules China forever. Liu Xiao Bo and Tan Zuo Ren are not terrorists, they are not advocating killing anybody.
How do you know democracy will cause 社会动荡? South Korea, Germany, Japan, Russia, Eastern Europe, Taiwan and many many other countries all had a peaceful transition to democracy, and yes, they are very stable now.
It's absolute rightly to be tough on our enemies, and the terrorists who want to kill us. Democratic countries are not weak countries or we would not have won the hot war against Nazi and cold war against the communist Soviet bloc. I support the country I am living in and our US, NATO allies and friends, I want my country to win, and enemies to lose. Clear enough for you?
If you want your country U.S. to win, that's your own problem, and we wouldn't say anything. but we support our own country, and that's our own business as a Chinese, so step away you American. CLEAR ENOUGH FOR YOU?