Of the panoply of challenges faced by the leader of a large democracy, some are perennial (when is the economy not an issue?) and usually of a low intensity; others are seasonal and high-stakes.

This week, Indian Prime Minister Narendra Modi has found his forbearance and strategic capabilities exercised to their fullest by a domestic crisis (to some citizens, a foreign policy one) partly of his own making. An ambitious political experiment engineered by Modi and his Hindu nationalist party in the border state of Jammu and Kashmir — the only Muslim-majority state in India — threatens to implode within just a few days of its inauguration.

The largest region within Jammu and Kashmir is the Kashmir Valley, the tinderbox of South Asia. The valley has been the subject of hostilities between India and Pakistan for seven decades, since the controversial accession, by its Hindu king, of the state of Kashmir to India in 1947.