The main thing that is holding Pakistan together is the Military and somewhat the religion, which has been used by so many rulers-civilian and military to justify their rule that the meaning of it has gotten lost. The tolerance of other people’s faith and believes have gone down the drain and the society as a whole has become more radicalized and paranoid about everybody alien. On top of this, the unhealthy phobia of India, their next door neighbor has clouded the mindset of its people and military. They have been obsessed with India in all things possible. This is a nuclear armed nation which has the fastest growing nuclear arsenal in the world but it is also the fact that the nation as a whole has lost its meaning.
Even the official name of “Islamic Republic of Pakistan” does not hold true as the name of Islam has been distorted and used for their own political gains by different politicians and the Military. It is a nation of four or five different nationalities who have nothing in common except the religion. The people in that nation think that everybody is out to destroy them and take hold of their nuclear assets. But on saner thought (which is increasingly rare there), it would be really insane to break that nation apart since it is more easier to handle one Pakistan than to divide it into four and five parts and deal with the consequences. We have all see this picture in Iraq. So in one case the holding together of Pakistan as one by the Military in one form or the other is the best scenario right now.