(CNN)-China will sometimes say "no" and the world should get used to it. That message came through when China joined Russia in blocking action on Syria. "Do not mistakenly think that because China takes a careful and responsible position on the Syria issue, China will not use its veto power   or will always abstain ," said Cui Tiankai, China's vice foreign minister, "When China must use its veto power to say no, it will surely use it." On Saturday, Susan Rice, the U.S. ambassador to the United Nations, called the vetoes "disgusting and shameful." He Wenping, director of African Studies at the Chinese Academy of Social Sciences, said the veto shows China's confidence in foreign affairs. "A country expressing its true opinion - that's progress. China opposes the use of threat or force to achieve regime change in other countries. This agrees with China's long-standing diplomacy principle. It is also not acceptable for China to rush a U.N. vote without sufficient discussion." So why did China use its veto this time? China's critics say China's veto of the U.N. draft proposal  was in part due to Beijing's fear that allowing a regime change in Syria could encourage the spread of the Arab revolution and eventually threaten China. He Wenping disagrees, "China has a completely different political system and economic development path. If someone in the international community thinks that the Arab Spring will happen in China, then I think they misjudge the situation in China, exaggerate  some problems in the Chinese society and underestimate the ability of the Chinese government to control the situation in China." Why did China use its veto power this time?
Because Russia and China are friends. Because China wants to hold an opposite stand against the U.S. Because China is worried about a chain-action resulting from Syria's revolution. Because China opposes the use of threat or force to achieve regime change in other countries.