Source: Energy Information Administration, World Oil Transit Chokepoints & BP Statistical Review of World Energy.
In addition to geopolitics, the geography of the Middle East creates challenges for petroleum distribution. The first is the concentration of reserves around the Persian Gulf (Saudi Arabia, Kuwait, Iraq, Iran, and United Arab Emirates) leaving the Strait Hormuz as one of the only viable outlets to export oil using large oil tankers. The second is the constrained access to the main European markets through the Suez Canal, implying that a fully laden VLCC (Very Large Crude Carrier) cannot transit through the canal and must round Africa.