It is an oft quoted economic statement that a $1 dollar rise in the price of oil adds 0.1% to inflation over 2 years. The Libyan war added approximately 20% to the price of oil overnight. This has coincided with a very weak patch of the world economy.
There are many current parallels to 2008 at the moment; volatile markets, banks in trouble, leverage and debt issues to the fore and a macro economic collapse possible.
However, the role of the price of oil is not to be underestimated. In 2008 when the price of oil hit $147 a barrel a deep recession kicked off very soon after. The price of oil promptly collapsed and as a result inflation only spiked rather than went into over-drive; also the recession, whilst deep, was shallow (clearly QE and other externalities played a role here).
As the global price of oil has ticked up again through 2010 and now 2011, it is no coincidence that the Western Economies have faltered for growth. Oil is a key driver in inflation but also for manufacturing and transport. High oil prices create demand destruction in our economies as there is as yet no real replacement for it at a competitive price.
Cause and effect are always hard to identify at a macro level, but the sudden rise of oil in 2008 is exactly before the 2008 collapse, as is the rise back up to today's levels also starting to affect the UK GDP growth of 2010.