Modi is a seasoned politician, there is nothing to suggest that he believes that Pakistan will keel & roll over. That can be understood by his act of calling the Pakistani PM for his swearing in, that alone would have disappointed a whole horde of his fans. Modi is in the middle of an election campaign taking flak for not being available to deal with the situation on the border. Hardly something he would have chosen to deliberately engineer. While we will disagree about who started this, I can only point out there is very little logic for Indians having deliberately escalated without provocation. The PM has had, as reported in India, a highly successful visit to the U.S. where by all accounts he ignored Pakistan. Makes no sense to bring Pakistan back into the limelight by firing at the border, not something that will have immediate effect either militarily or diplomatically & certainly not politically.
As for showing no quarter, no one is asking you to. The Indian army will take care of its business, just as it did last year under a different government. The border has been live for a substantial period of time, it will take a great deal of cussedness to suggest that this is somehow Modi's doing.
You think that is what happens with small arms and mortar fire?