Even as investigative agencies gather evidence (the Taliban has claimed responsibility but they might not be the only ones responsible), a few questions arise immediately.
First, is this a reaction to India's growing influence in Afghanistan? The answer is yes and no. Yes, there is certainly concern within Pakistan that India's activities in Afghanistan are giving it 'strategic depth' at a level that makes Pakistan uncomfortable. No, India's development-related activities in Afghanistan cannot be a justification for wanton acts of terror.
India has no military presence in Afghanistan. It has built a 281 KM road that connects the landlocked country to Iran (and by extension to seaports). It has installed a new power transmission line to bring 24-hour electricity to Kabul. In addition, there are projects for building hospitals, women's training, administrative training, hydropower, solar power, etc. (A fuller listing of development activities can be found here.) Unlike other countries which have built fortresses out of their embassies, and despite the bombings last year as well, India has refused to move its embassy out of a commercial part of Kabul. India believes that a simultaneous and fuller engagement in many sectors of Afghan society and economy is a more constructive approach to nation building than merely military activities.
Many argue that this is mere hogwash, that India has ulterior motives in giving more than $1 billion in aid and that this is just another segment of the Great Game. At one level, this is an obvious point. All official development assistance has explicit political purposes. No one can dispute that. Further, all countries have intelligence assets in regions where their national interests are affected, including in friendly countries. The question should not be whether India has interests in Afghanistan, but how is it exercising its influence? To suggest that development assistance has political motives would imply that diplomatic contact between sovereign states cannot ever be possible without hints of political suspicion. More importantly, there is a tendency to paint the actions of different countries differently. Thus, NATO/western assistance is meant to 'win hearts and minds' whereas Indian assistance is called 'meddling' in Afghanistan's affairs. Diplomacy is the art of finding common interests. The explicit Indian and Afghan position is that it is mutually beneficial for both countries that India engage in development activities there rather than put troops on the ground. This is why India's activities in Afghanistan cannot be equated to NATO's; nor can terrorism against Indian civilians (diplomats as well as private workers, road-builders, engineers, medical personnel, teachers, administrators) be justified.
A second question: do these attacks prove that India (and Kashmir) must be roped in an Af-Pak strategy? This was the original plan of the Obama administration. But there is a serious risk in linking Kashmir to the Af-Pak issue. Just because groups linked to the Taliban are tactically deployed in Kashmir does not make it the same problem. Linking the two would be only a short-term military tactic; it would not resolve the underlying political factors that drive the two conflicts. The administration believes that resolving the Kashmir problem (or in the least easing tensions between India and Pakistan) would free up Pakistani forces to fight the Taliban on its western border. But this would not necessarily increase political stability in Afghanistan. The Af-Pak border has never been accepted by the Pashtuns, an ethnic-political grievance that has taken on religious dimensions. That is a political issue that Pakistan and Afghanistan would have to resolve together - and it is going to be a long process. Kashmir has nothing to do with it. That does not mean that Pakistan's tensions with India do not distract it from the Afghan war effort. The point is that the problems are different and need different political solutions. What is militarily imperative in the short term is not a long-term political solution.