Political analysts say that Indians are rallying behind Mr. Modi again, and that he seems to be making crucial gains among independent and undecided voters.

The fact that India’s airstrikes probably missed their targets, and that a fighter jet was shot down by Pakistan, doesn’t seem to matter to most Indians. Their country was hit, and Mr. Modi hit back.

“Even if they go below the seven seas, I will find them,” Mr. Modi said in a speech this month, referring to terrorists. “To settle the score is my habit!”

Some of his supporters in India see Mr. Modi’s aggressive stance not as pandering for votes, but as a return to his old passion and focus.

“Whatever our criticisms about him regarding the economy and jobs, at the end of the day he has done an incredible job of delivering justice for the martyrs,” said Prapti Bhattacharya, a law student and first-time voter.

“Before this, I would have voted for Congress,” the leading opposition party, she said. “Now I’m voting for Modi.”

The Pakistan crisis “has provided him with a golden narrative,” said Milan Vaishnav, the director of the South Asia Program at the Carnegie Endowment for International Peace. “The thing about a national security crisis is that it plays up decisiveness, leadership and nationalism. These are three characteristics he often touts.”