WAJsal has alluded to the obstacles in the way of Pakistan's system meeting the standards set by the western world, but he doesn't seem to give any suggestions on as to how we should go about doing that. Military intervention is merely one of the many facets of those obstacles and one that is increasingly used by the corrupt political dynasties as a scapegoat to blame for their own corruption incompetencies. In Pakistan's case, It merely slows down the process of political reforms but unfortunately no decisive attempts are being made to that end.
Let's talk about political reforms. Here I would suggest to readers the study of the working of the Parliment, its history and also the contrast between the nomination of prospective parliamentary candidates in Pakistan and the western world. Britan would be a good place to start. The problem, as you have pointed out, is the complete domination of dynastic politics headed by business tycoons and landowners, you can call them the second estate, though second to none in rank, or Pakistan's very own Lord Temporals If you will. The only difference is that they sit in both the upper and the lower houses. There is the clergy, of course, but comparatively of little consequence in the politics. These Lord Spiritual equivalents tend to claw at the political systems from the outside of the Parliment. Our political lairds run their political parties by nominating smaller landowners, sons of landgrabbers and the like, in exchange for inducements that cannot possibly be afforded by the honest-to-god people we would like to be governed by. Another unfortunate reality, one that cannot be helped (not right away in any case) is the electorate, no more sane than a crowd from the middle ages cheering for the executioner, which decides to vote based on unqualified intuition and the charm of his laird.
The way to initiate these political reforms would be to set up a political party headed by well-known intellectuals of one mind, with a clearly defined party politics, charter and manifesto. Not a conservative party, not a liberal party but a labour party. But this time, it would not be headed by the landowner Bhutto but by the people. This party will nominate its candidates with selection committees composed of upstanding citizens and will nominate candidates based on merit and merit alone. Only this sort of representation will get you the political reforms at the pace they're needed. As for the Judicial reforms, they're trickled down from the legislative assembly. So political reforms should be the primary concern here.
It's true that these reforms are badly needed but as the old saying goes "who will bell the cat". These reforms can only be made by the people who genuinely care for the country, the system and the people. We lack those kind of people in our top leadership, parliament and other institutions who hold the power to introduce such reforms.
Personally I'm of the view that a new system(or a heavily modified version of the current, essentially making it new) is needed where human nature is taken into account. Exactly like when u put a lion in the zoo, u take the necessary precautions keeping in mind it's nature.
Over centuries as people realized the dangers of immense power in the hands of one man for his entire life(monarch), they moved to a new system. In this system(democracy) ideas such as limited terms, separation of powers, checks and balances were introduced. This takes into account the human nature of where power can go to our heads and essentially puts a stop to it(for the most part).
However there is a second element that has always existed in every form of government and might always exist unless a new system is introduced that puts a check on that. This second element in every form of government is money. Money and power have always been coupled throughout history.
Examples:
Emperor(Power)/Aristocrats(Money) - Europe/Elsewhere
Emperor(Power)/Shoguns(Aristocrat with an army) - Japan
Consuls/Emperor(Power)/Senators(Money) - Rome
this coupling of money and power was hardly addressed in the system called democracy and this is why it still plagues us. The idea behind it was noble(a government for the people by the people) but overtime that government became more and more like an elite club with a few select members that collectively rule(if not one then another). This is definitely true in case of Pakistan(parliamentary democracy) and just as true in the US(a representative democracy).
A system built on the following maybe a step in the right direction.
New - Separation of money and power
Old - Separation of Powers
Old - Checks and Balances
Add to this some stern accountability and there might be a system that has the least amount of sold out/corrupt ppl working for self interest. Coming up with such a system would probably be very hard.