In truth, the strike itself does not represent a radical new policy. India conducted local cross-border raids through the 1990s and 2000s, usually as reprisals for particular attacks. But this high-altitude, tit-for-tat war on the Line of Control, which divides Indian and Pakistani-controlled parts of Kashmir, was largely unknown to the Indian public, who grew frustrated at their government's apparent inaction.
India's decision to go public in dramatic fashion is therefore a break with the past.
Why did Modi take this step?
Domestic politics is part of the answer. After a terrorist attack earlier this month that killed 18 soldiers in Kashmir, a senior leader of Modi's party, the Bharatiya Janata Party, demanded severe retaliation: "Pakistan is a terrorist state," tweeted Modi's home minister, "and it should be identified and isolated as such."
Retired generals, diplomats and news anchors demanded that Pakistan be given a "bloody nose."
This is a way of signaling that New Delhi's patience has run out, and that India might escalate further next time.
At the same time, it should be remembered that this was a relatively modest operation. It was restricted to disputed territory, allowing India to claim it remained within what it considers to be its own soil. It also deliberately focused on militants, rather than Pakistani troops, which would have been more provocative.
Overall, India remains constrained in what it can do to Pakistan for fear of a larger war, the associated nuclear risks, and the impact on India's own diplomatic and economic well-being.
Pakistan has initially denied that India crossed the border at all, and this policy may help it save it face. But we are likely to see tensions grow, and the Pakistan army may retaliate with intensified shelling, attacks on Indian troops in Kashmir or terrorist attacks elsewhere in India or on Indian interests in Afghanistan.
The present Pakistan army chief is due to retire in a month, and the views of his successor -- technically chosen by the elected government -- will also be of great importance. The more Modi gloats, the more Pakistan will be compelled to show it remains unbowed.
This dynamic could result in a rocky few months in South Asia.