U.S. strategy in WWII was to keep all its future economic competitors fighting as long as possible, and then to emerge from the war as the pre-eminent world power, due to the weakened state of all the pre-war powers. It would be logical for China to sit on the sidelines of any war against Iran, watch the U.S. drain its resources, and weaken itself. Even if the U.S. wins the war with no major casualties, the primary victor will be China.
U.S. and Russia discuss flight safety in Syria on conference call (Reuters)
from the article: Iran: We will cut oil flow if West imposes economic sanctions