Betweenness centrality measures the capability of the nodes as mediums in the network. It can also be
explained as the extent to which the node controls the trade flow. In the international crude oil trade
network, betweenness centrality is the frequency a country stands on the shortest path between two other
countries. Fig.2 shows the betweenness centralities of five countries. From Fig.2 we can see that USA has
the highest control ability. The control ability of China ascends eventually with fluctuation before 2000,
descends a little from 2002 to 2008, rises to a peak in 2010 and drops a little in 2011 and 2012. The entire
tendency of China ascends and the level of China’s control ability in the international crude oil trade is
more or less equal to Russia and Netherlands, far below USA and a little higher than Japan.