Can someone please explain the whole blood for oil/invade iran shit?

[kahljorn]

I would also like an explanation of why gas prices are so high, when they used to be so low.

I just don't understand why gas prices should have increased. There's no causal connection between the war in Iraq and oil prices -- or there shouldn't be any, legitimately. Unless it caused a problem with US foreign trade relations. Or if it's just some type of general economic problem that just happens to influence gas prices. Maybe gas prices were rising before the Iraq war, and I am just assuming that they supposedly have a connection -- that could be a possibility.
Do wars always make gas prices go up? is it basically a tax? has gas or oil gotten more expensive to produce/get? is there a lot less of it because of foreign trade relations? I don't really get it :O