Is the right to self defense the only unilateral exception to the use of force?

This is in relation to the UN charter and the prohibition on the use of force as set out in article 2(4). I want to know that does the school of though that argues for preventive war ie Bush doctrine- does this fall within the remit of self-defense or does it allow for unilateral action by states?|||that or if you want thier oil i guess. or if they're not white seems to be a popular one too.|||personally i think people will see if it was a good thing or bad thing in the future and as for the golden buffalo, name one barrel of oil that we have brought out of iraq, do you not go out side, do you realize how much it cost due to not having it, you might as well say the sky is green