The seizure of Venezuelan President Nicolas Maduro poses a major headache for China, a close political ally of Caracas and major importer of Venezuelan oil. Ever since the era of authoritarian leader Hugo Chávez, Venezuela has been China’s most consistent partner in the Americas. Beijing has staunchly supported the Maduro government. The friendship has helped China expand its presence in a region the US considers its back yard. But China's carefuly developed ties to Venezuela could now be in