It was intended as the conclusion of the Metal Gear Solid story, a fact that was played up throughout the game's marketing - most trailers showed Snake seemingly committing suicide at the conclusion of his mission.

Metal Gear Solid 4: Guns of the Patriots takes place in 2014, around 5 years after the events of MGS2, and sees an aged Solid Snake (now dubbed 'Old Snake') on his final mission to stop Liquid Ocelot and his PMC armies once and for all.