Before becoming prime minister, India's Narendra Modi was barred from receiving a visa to visit the U.S. A rising leader in the Hindu nationalist Bharatiya Janata Party (BJP), he was tied to deadly sectarian violence. But now, backed by an overwhelming parliamentary majority, he leads one of Asia's most important powers. The Obama administration rolled out the red carpet when he visited.

India won independence in 1947, but was born in violence when Britain divided the vast colony into majority Hindu India and largely Muslim Pakistan. Millions fled their ancestral lands and hundreds of thousands died in the process. The two nations fought bitterly and repeatedly. Kashmir, a territory allocated to India because a Hindu prince ruled over a Muslim majority, remains a source of conflict. New Delhi proudly asserted its international independence, participating in the "non-aligned" movement while trending toward the Soviet Union. Yet India found itself at war with China, losing territory to its equally populous and impoverished neighbor.

New Delhi long was ruled by the dynastic India National Congress Party, which enshrined dirigiste economics as the state's secular religion. As a result, a land which spawned a global network of entrepreneurs and traders remained desperately poor, its people suffering under myriad rules, regulations, procedures and laws. The government bureaucracy was legendary for its determination to obstruct any good idea; litigants sometimes died waiting for the sclerotic legal system to act. As much of the world embraced market economics India remained wedded to the socialist illusion.

Eventually, however, reality seeped into New Delhi. The Congress Party liberalized the economy. The BJP broke the Congress monopoly on power. India joined the global nuclear weapons club. New Delhi appeared ready to follow the People's Republic of China to international superstar status. But then enthusiasm for economic reform ebbed, economic growth slowed, and conflict with Pakistan flared. India again played the underachiever: poised at the cusp of great economic success and diplomatic influence, New Delhi seemed to fall back on its old ways.

However, with Modi at its helm the BJP recently handed the Congress Party the latter's greatest defeat ever. On May 26, Narendra Modi became prime minister. He recently visited the U.S. to speak before the United Nations and meet with President Barack Obama.

Of course, there was that embarrassing visa ban, the only one ever issued for that reason by Washington. It is one thing to prevent a controversial provincial leader from visiting America. It is quite another thing to bar a sitting prime minister, and the leader of a nation with which Washington desires improved relations -- especially since America routinely has engaged far worse world leaders. So the matter was quietly forgotten, though the underlying issue never was resolved.

While serving as the chief minister of the state of Gujarat in 2002 Modi was implicated in Hindu riots which killed more than 1200 people, mostly Muslims, and forced 150,000 people from their homes. It was generally agreed that some in his government were complicit in the violence and lesser officials were convicted. However, Modi escaped responsibility -- some proclaimed him innocent, others contended that evidence had been destroyed.

A number of his partisans simply argued, some in splenetic responses to my earlier writing on the subject, that those killed deserved their fate since other, unnamed Muslims may have caused the deaths of three score Hindus in the train fire which triggered the mob attacks. Christians also have suffered from periodic violent spasms in BJP strongholds, triggering similar rationalizations from Hindu nationalists. How dare missionaries care for the lower caste poor traditionally left behind in Indian society? Obviously, Hindus who convert are brainless and do so only for money. Such is the vicious mindset which abets murderous violence. Indeed, the number of attacks on religious minorities by Hindu extremists is up this year, though Modi has not encouraged the trend.

Rather, Modi so far has focused on India's future. He was elected to reform the sputtering economy, which would not be helped by fueling religious hatred. To date his administration appears to be pragmatic and practical. He should work to dampen sectarian hatreds and violence.

The prime minister's visit to America offers an opportunity for a reset in bilateral relations. The Bush administration made a major push to improve ties by accepting New Delhi's development of nuclear weapons, in contrast to the Clinton administration, which imposed economic sanctions. But little progress has occurred during the current administration, despite a meeting of the U.S.-India Strategic Dialogue in 2010. Indeed, controversies over trade policy and criminal charges against an Indian diplomat put the two governments at sharp odds.

The result is a lost opportunity for both nations. Obviously, only the people of India can set their country's course. However, by hobbling the economy New Delhi's political elites have kept the great mass of people poor and dependent. Nor is the country as influential as it otherwise would be. For Beijing political influence has followed commerce and investment. The PRC now trades more with South Korea than does America. China's economic missions circle the globe, building links with Southeast Asia, Africa, and Latin America.

India, which, based on purchasing power parity, trails only America and China economically, so far performs far below its potential. India's per capita income comes in at 130 to 140 in the world. Modi naturally hopes to expand his nation's commercial ties throughout Asia, which increasingly is the world's economic center of gravity. But America remains the most important single state -- with the largest (depending on measure), most sophisticated, and wealthiest economy. Almost certainly economic development will remain Modi's first priority, despite a disappointing, largely reform-free first budget. He cannot afford to let time for reform to slip by.

Geopolitically, India has yet to play the international game as well as possible, though the new prime minister embarked upon an ambitious travel schedule abroad. New Delhi's most persistent foreign antagonist is Pakistan. America's ties with Islamabad are both historic and current, most closely tied to the war in Afghanistan. The Bush-era warming of U.S.-India relations rocked Pakistan; building closer and more enduring ties with America would help New Delhi wean Washington away from its tight Pakistani embrace, one that already makes many U.S. policymakers uncomfortable.

More important in the long-term is India's desire to develop international counterweights to China even while cooperating economically. Beijing remains well ahead of Delhi in most military and economic measures of power. Indeed, for years the PRC has dismissed India's potential. However, New Delhi is proving that India matters, for instance competing economically with China in Burma, which recently shifted Westward away from Beijing, and conducting naval maneuvers with Vietnam, which recently endured Beijing's aggressive territorial claims. Prime Minister Modi has visited Tokyo, strengthening ties with another wealthy industrialized state as well as emerging counterweight to the PRC.

The greatest prize for Modi would be the U.S. Former Indian diplomat T.P. Sreenivasan argued that economics will cause New Delhi to view America of "primary interest." Earlier this year Modi declared that "The oldest democracy in the world and the largest democracy in the world are natural allies." In an interview with CNN's Fareed Zakaria, the prime minister cited the recent improvement in bilateral relations and explained: "Our ties have deepened. India and the United States of America are bound together, by history and by culture. These ties will deepen further."

Washington is thinking in similar terms. When Secretary of State John Kerry visited New Delhi in July, he said he wanted the two nations to become "indispensable partners." President Obama presumably used his meetings with Modi to make the same point.

No one expects a formal military alliance, which would be in neither nation's interest. And important issues will continue to divide the two capitals. But friendlier political relations, increased security cooperation, and enhanced trade and investment would remind the PRC that its growing power is matched by that of its wary neighbors. More frequent visits and summits between Indian and American officials also would reinforce New Delhi's importance to the U.S. So would Washington's support for India's ascension to the UN Security Council, an objective advanced by Modi in his General Assembly speech.

No doubt the Obama administration feels overwhelmed. The U.S. faces another counterproductive, even disastrous Middle Eastern war, continuing confrontation with Russia over Ukraine, clamorous European allies demanding that Washington relieve them of responsibility for their own defense, Chinese assertiveness throughout East Asia, Asian allies also demanding American protection, North Korean hostage-taking in an attempt to force U.S. engagement, and a host of domestic economic and political problems. Who has time for India?

But make time President Obama must. India matters today. It will matter much more tomorrow, especially if Prime Minister Modi commits his political capital to eliminate barriers to entrepreneurship, investment and growth. China leads New Delhi, but remains an uncertain superpower, with a skewed demographic structure and authoritarian political system. India has further to travel to geopolitical greatness, but with economic reform its people would prove to be its ultimate resource. Moreover, New Delhi's always messy politics could ultimately prove to be one of its greatest strengths, giving the Indian people the ability to shape their own destiny rather than have it imposed on them. Modi, with his record as a Hindu nationalist, is well-positioned to insist religious and social tolerance.

The 21st Century will be the Asian century, with a major assist from the United States. Most analysts presume Chinese dominance, but India could prove them wrong. If Barack Obama and Narendra Modi continue to make a serious effort to overcome past differences, their governments could find themselves, like Rick and Captain Renault in the movie Casablanca, at the "beginning of a beautiful friendship."