They were all walking along when they found a magic lamp...
A genie popped out and said, "I will grant each of you a wish. What do you desire?"

The Canadian Farmer said, "I wish for fertile lands for all eternity." The Genie says, "It is granted."

OBL asked, "I wish for a huge wall to be built to enclose Iran, Iraq, Pakistand and A-Stan for all of eternity, to keep out the infidels!" The Genie says, "It is granted."

The Marine steps up and asked OBL a question first, "How big IS this wall you have wished to be built?"

OBL replies, "Five Thousand Feet High, Five Hundred Feet Thick! Why do you ask infidel?"

The Marine turns to look at the Genie and says, "Fill it with Water!"

Nice

Good one