Most pollsters say Indian Prime Minister Narendra Modi will win a second five-year term in a general election that began on Thursday to elect parliament’s lower house. As Indians vote across one million polling stations over five weeks, the question is whether their attention, recently focused on border clashes with Pakistan, has returned to a lackluster economy.

Mr. Modi’s Bharatiya Janata Party-led coalition is riding a surge of nationalism after a February terrorist attack in Kashmir by Pakistan-based jihadists killed 40 Indian paramilitary troops. Indians cheered a retaliatory airstrike on a suspected militant camp in Pakistan, boosting Mr. Modi’s national-security bona fides.

But the leader Indians elected five years ago was an economic warrior. Voters in 2014 gave Mr. Modi a rare mandate to unshackle India from the welfare policies and hostility to foreign investment that characterized decades of Congress Party rule. Five years on, those who hoped for reform are disappointed.

There’s been some good news. India has climbed 53 spots over the past two years in the World Bank’s Doing Business index, reducing wait times for construction permits and improving access to electricity. Credit markets have also strengthened with expedited insolvency procedures in a new bankruptcy code. A 2017 goods-and-services tax, despite a sloppy rollout, replaced a gnarled web of local taxes that crimped interstate commerce.