There's a fundamental difference between tankers and pipelines... pipelines only go to one place. A country with an oil port, say Saudi Arabia, can load tankers going to a dozen different destinations at the same time. Kazakhstan or Turkmenistan are limited to where the pipelines go. Cuts the options a bit.
One reality of the oil business is that a kink in anyone's hose affects everyone else. If the Chinese hose from Kazakhstan gets kinked, the Chinese won't stop burning oil. They'll buy on the spot market, push the price up, and compete to buy the oil that other buyers are now getting. Because they have lots of money, they can compete quite effectively. Just because Angola sells to China and Nigeria sells to the US doesn't mean Angolan oil is "Chinese supply" or Nigerian oil is "American oil". Either will sell to the highest bidder, like everybody else.
Cutting off oil supply from one country to another is not quite the weapon it's sometimes thought to be. It doesn't starve that country, just pushes the price up for everyone.
Bookmarks