I think there are several factors that need to be noted.
Political Culture - in the colonial era authoritarianism remained more deeply entrenched in the areas that now constitute Pakistan compared with the rest of India. These areas were acquired for strategic rather than commercial reasons and were annexed much later by Britian. In relation to the this, Tan Tai Yong has argued that Punjab’s key role as a recruiting ground for the Indian army during colonial times, meant it was in Britain’s interest to ensure that the state remained placid and military interests were protected. What emerged as a result according to Tan Tai Yong was a civil-military state in the Punjab. There was an entrenchment, a convergence and a nexus of interests between the bureaucracy, the military and rural notables. The foundations were therefore already in place for a civil-military alliance to take control of the state apparatus at the time of Pakistan's birth. This contrasts with rest of India where there was a growing politicisation before the end of the Raj leading to a political culture at independence that was conducive to a democratic ethos and the presence of a ruling elite schooled in and believing in the merits of democracy.
Political parties - By 1947 the Muslim League remained a ramshackle organisation dependent on its unity mainly on the cause of Pakistan and the moral leadership of Jinnah. Many landlords jumped on the Muslim League bandwagon in the 1940s. Many of them were known more for their opportunism and factionalism than ideological commitment. Once Pakistan was achieved it was not surprising that the Muslim League disintegrated as landlords squabbled. Jinnah worked hard in the last decade to strengthen the party, but 10 years was simply not enough to transform it into a strong institution. Indeed it must be remembered that the struggle for Pakistan was only for 7 years, and that its creation only became inevitable after 1946. There was not enough time for Muslim League to institutionalise the mass support or to prepare for independent statehood. In popular conceptions, Pakistan symbolised the unity of Muslims and the individual commitment of Muslims to Islam. But this was an aspirational vision, rather than one which was a detailed blue-print of for the exercise of state power in an independent Muslim state. It could be argued that the lack of a shared and nuanced vision halted the constitution making process. On the other hand, the Congress party had become more strongly institutionalised by 1947 and had experience of government and as an ‘umbrella’ party was able to deal with the processes of bargaining and accommodation to become the dominant party. The Congress well before independence had looked to address potential interference from the army. Such discussions were absent in the Muslim League. India also took a number of important steps to reduce the likelihood of a coup after independence. To point to just a couple: in 1947, the Commander in Chief was removed from Cabinet and made to report to the Defence Minister. In 1955 the Commander in Chief’s power was also reduced within in the military, when they were downgraded to the new position of “Chief of Army Staff.” This in fact encouraged interservice rivalries making successful coordination much more difficult.
Effect of Partition - Pakistan faced massive problems at the time of partition and was ill-equipped for independent statehood. Pakistan soon after its birth was battling to survive and barely a going-concern. Having to carve out a new institutional structure, linking provinces to a new centre and that too in financially difficult circumstances, severely hampered the development of a democratic process, with an emphasis instead on consolidating the state. Pakistan also had to guard the north-west frontier (a massive cost burden on its own) as well as the new border with India with meagre tax revenues. The lack of strategic depth in Pakistan and the perceived threat of India led to an effort to strengthen the army as well as an emphasis on an over-centralised state. Maintaining territorial integrity was viewed as more crucial than developing democracy. The greater sense of insecurity Pakistan felt, also encouraged Pakistani elites to seek assistance from the US, cementing the international connections between bureaucrats and military officials and Washington, which helped the army achieve pre-eminence in the cold war context. In addition Mohammad Waseem has drawn attention to the fact that many of the Muslim League politicians upon migration to the new land lost their local power bases. Clearly there existed an incentive not to hold elections for these politicians. India on the other hand inherited the British Raj’s unitary centre, the bureaucracy and the personality of British India. It was on stronger economic and strategic foundations and did not face the same financial constraints as Pakistan. The size of India also made military takeover much more difficult owing the level of co-ordination required.
Social and economic Structure - the dominance of landlords in Punjab, the demographic majority of Punjab in West Pakistan, but the demographic majority of Bengal overall in Pakistan, the dominance in the army of northern Punjabis, the stark divisions between West and East Pakistan, the high number of refugees as a proportion of the population, were all factors less favourable in promoting democracy as they undermined stability. India on the other hand had a social structure marked by incredible diversity which meant no one group had a majority. Division based on caste also made collective action to overthrow a democratic regime very difficult, as Perry Anderson has recently argued. It needs to be stated as well that the Pakistan army was highly ethnically imbalanced. In Pakistan – unlike India – the massive Punjabi overrepresentation in the army (a colonial inheritance) was not cross-cut by other cleavages. As Morris Janowitz, has noted “armies with high internal cohesion will have greater capacity to intervene in domestic politics.”
