Since independence in 1947 Pakistan has had three coups by the armed forces. The present head of the military General Parvez Kayani is very much opposed to a coup a position certainly not shared by some of his predecessors.
Many think that President Zardari was behind the so-called coup memo. This memo was a letter to the U.S. military commander Admiral Mullen that sought his support in ousting key members of the military leadership. In the memo as well the military were accused of planning a coup after the U.S. killed Osama bin Laden without informing Pakistan until it was already in process.
An anonymous military source claimed that the opposition and most Pakistanis were fed up with Zardari not just the army. The U.S. had dismissed the allegations about a military coup in the memo they received as simply not credible. The Pakistan Supreme Court is considering a petition that requests an inquiry into the memo affair.
The ruling party worries not just about the military but about the courts whom they fear may be out to get Zardari. Prime Minister Yusuf Gilani said: "Let me make clear to you today that there are intrigues, conspiracies afoot to pack up the elected government," As usual there is political strife brewing in Pakistan. For more see this article and also here.