Another problem that we may be facing, although it may not be the direct cause of this weeks rise in prices, is peak oil. If we haven't already reached it, then we are expected to in the near future. After that, we won't be able to get as much oil out of the ground profitably. This would cause prices to rise.
I have recently learned about the best first principle in college, which states that any organism, including people, will take the largest, most accessible sources of energy before moving on to lower quality sources. This applies to how we have collected oil. So, although there are still sources, such as the tar pits in Canada, they are not nearly as good as the ones that we have used up.
On top of this, because the global population is growing exponentially (over more than doubled in the last 50 years) oil is being used up faster than it ever was before and is in higher demand than before.
The last time the US nation saw anything like what the overall result would be was when our domestic oil peaked around 1970.
Here are the names of a few scientists who have studied the areas that I have mentioned above, in case you want to have a starting point if you are interested in verifying my information:
M. King Hubbert, Dr. Albert Bartlett, Dr. Charles Hall