ahhhh, well,,,, even if u know what happened in the past games. -which by the way 5 games-
Metal Gear 1
Metal Gear 2
Metal Gear Solid 1
Metal Gear Solid 2
Metal Gear Solid 3
and some additional games like
Metal Gear Acid
Metal Gear Twin Snakes
Metal Gear Portable Ops
...
trust me, u will not understand what's goin on in Metal Gear Solid 4..
just get it..