India, the world’s biggest democracy, delivered a huge mandate for change when it gave an overwhelming victory to the Bharatiya Janata Party (BJP) and Narendra Modi, who will officially become prime minister on Monday.

Elected with soaring expectations, Modi must now deliver on his campaign pledge to revive India’s sclerotic economy. At the same time, he must temper the BJP’s Hindu nationalism, which threatens to further alienate and marginalize the country’s 165 million Muslim minority. The economic goal, in particular, is of critical interest to the United States.

The high hopes are based on Modi’s bureaucracy-busting in Gujarat, the Indian state where he was the top elected official. Despite the image of the burgeoning “BRIC” (Brazil, Russia, India and China) economy, India’s once-stellar growth has stagnated. Many blame an inefficient, incompetent and corrupt bureaucracy, which Modi took on with relish and success as he led Gujarat to outperform other Indian states.

Getting the nation growing more quickly would not only help lift more citizens out of poverty, but could kick-start the moribund global economy. The Indian stock market seems convinced — it soared on the news not just of the BJP’s victory, but of the margin: The BJP won 282 seats in Parliament, which means it will not have to cobble together a coalition to govern. Comparatively, the incumbent Congress Party won only 44 seats despite its defining role in ruling India during most of its independence.

Modi, the son of a tea seller, deftly contrasted his humble background with that of Rahul Ghandi, the scion to the Ghandi-Nehru dynasty. The Congress Party’s devastating defeat suggests that the party will have to re-examine its future, and perhaps move away from its past, since India seems to have moved on from its founding party to focus on its current economic, social and political challenges.

Modi’s success in Gujarat was tainted by his alleged failure to protect Muslims during deadly 2002 riots that killed more than 1,000 citizens, mostly Muslims. In fact, the United States refused to grant Modi a visa in 2005 because of the allegations. While he has been cleared by the Indian judicial system, his actions — or inaction — coupled with his Hindu nationalist rhetoric, threaten to erode India’s long history of thriving as a multifaith, multiethnic nation.

U.S.-India relations will not hinge on the visa issue, however. As a head of state, Modi can travel to the United States, and President Obama not only offered his congratulations but invited him here. A productive bilateral relationship is important, if not imperative, for both sides, but especially for Modi as he establishes a better-defined foreign policy.

Compared with his well-established positions on reviving the economy, far less is known about Modi’s approach globally. Considering the long history of hostility toward neighboring nations like Pakistan, which like India has nuclear weapons, and Bangladesh, it would be wise for Modi to modify the BJP’s Hindu nationalism. This would not only help reduce tensions but advance Modi’s main goal of growing India’s economy. A rising India could also better counterbalance China, the tacit objective of Obama’s diplomatic pivot to Asia.

Modi’s mandate gives him an opportunity few world leaders currently enjoy. He was duly, democratically elected with a massive majority. If he channels Indians’ deep desire for a new economic direction to reform his country, he stands to succeed. If, however, he uses his historic opportunity to deepen divides, then he will squander his, and India’s, opportunity for a fresh start.

Secretary of State John Kerry was right when he said on Tuesday, “The friendship between the world’s oldest democracy and the world’s largest democracy is absolutely vital, and the United States is deeply invested in our strategic relationship.”